Carefree jingle writer Charlie Harper has his lifestyle altered when his uptight brother and his 10-year-old nephew move in with him.

Despite warnings from Charlie, Jake continues to feed seagulls on the deck and the birds invade the house. Meanwhile, Charlie thinks Judith is taking advantage of Alan, who keeps going to her house to fix things.

Jake wants to go home to his mom after he gets sick, prompting Alan to think he's a failure as a husband and now as a father.

Charlie can't function when his housekeeper storms off because of Alan's constant complaints, so Alan tries desperately to woo her back. Meanwhile, Rose comes to Charlie for dating advice.

Alan and Charlie have encounters with some highly libidinous soccer moms, but with two very different outcomes.

The guys go to Evelyn's house to meet the new man she's dating, and Charlie realizes the man's daughter is a woman he's trying to avoid.

Judith is upset with Alan and Charlie when she learns that a surfer who uses Charlie's shower walks around half naked in front of Jake . Then Alan's worried when Judith and the surfer become friends.

Alan tricks Charlie into joining him and Judith in leading Jake and his classmates in the school's annual music show.

Realizing he's losing someone special, Charlie plans a Thanksgiving dinner to convince her he's a family guy and that she should be with him.

When Alan is surprised to see that Judith has had a makeover and is dating a man, he decides to have Charlie help him transform his image.

Berta's granddaughter spends the day at Charlie's, which isn't a problem until he learns she's a beautiful, rebellious 16-year-old.

Charlie nurses an ailing Alan back to health so they can go on a double date with two sisters, one of whom Charlie's been wanting to date for a long time.

Charlie's financial manager informs the carefree jingle writer that he spends money faster than his royalty checks come in, and now he must go on a budget.

Charlie invites a mysterious, slightly crazed woman to stay at the house until she can settle some family problems.

Charlie is perplexed when Frankie, the mysterious woman temporarily living in the Harper household, begins falling for Alan and not him.

Charlie's still brooding over Alan's choice of their cousin as Jake's guardian if both parents die when the boy has an accident while in his care and has to be rushed to the hospital.

Charlie is stunned to learn his ex-girlfriend is now a man.

Judith's devious siren sister stirs things up at Jake's 11th birthday party when she hits on Alan. Meanwhile, Evelyn brings alcohol and has a party of her own.

Jake's sullen mood baffles and bothers the family and prompts Alan and Judith to take him to a child psychologist.

Charlie plays a tricky game when he gets involved with Alan's divorce lawyer, who could make things difficult for Alan if she were, say, dumped by a self-centered lothario.

When Charlie discovers that Alan is sleepwalking, he believes it's related to his brother's lack of sex following his divorce, and comes up with a cure.

When Jake repeats one of Charlie's sexist remarks in front of Judith's support group, the women convince Judith to stop Jake's visits with his dad and Charlie.

Charlie has a pregnancy scare involving one of his one-night stands and decides to go for the big "V," and we're not talking Vegas.

Alan learns that Charlie belongs to an exclusive men's group, and he begs his brother to let him join.

Judith is dating Jake's pediatrician, and Alan is upset until Charlie points out that if she remarries, his alimony payments will end.

Charlie tries to save Jake from school suspension for giving his teacher (Missi Pyle) the finger by romancing her, but his several attempts fail every time.

Jake is very impressed and can't stop talking about his mother's new boyfriend, Dr. Melnick, which annoys Alan. While Evelyn borrows Charlie's car to help her impress a Saudi prince, because she wants to sell him real estate. When Charlie gets his car back, he discovers his mother's bra in the backseat. When he finds out why it's there he decides to trade in his car.

Charlie meets his match when he falls for a woman who's better at playing hard to get than he is.

Alan denies having shoplifted a toy as a child and fears he has a dark side, until Charlie admits he planted the toy on Alan to stay out of trouble himself.

Charlie and Alan hire Berta's sister to cater a party their mother has conned them into throwing for her.

Alan meets a woman named Nancy at a grocery store, who fulfills every single one of his desires, forcing Charlie to take care of Jake. After knowing Nancy for a few days Alan decides to ask her to marry him, prompting Charlie to try and talk him out of it, and he even gets help from the brothers' mother.

When Charlie leaves the house to avoid a date that he can't stand, he ends up at a coffee shop, where he meets his old girlfriend Lisa. He finds out that she broke up with her husband, and now has a child. Now he must try to convince Lisa that he's okay with her having a child. While Jake tries to justify to his father why he isn't doing so well in school.

Charlie tries to get Jake's approval on a theme song that he is hired to write for a television show, which is based on a comic book that Jake is a fan. While Alan finds out more about Rose (including how smart she is), when he spends more time with her.

After getting unusually turned down at a bar, Charlie learns that a website has been made dedicated to exposing his lifestyle. Charlie sets out to find who created the site, making amends to all those he stood up, but it's harder than it looks when all the women take the apology better than expected.

Alan is jealous of Charlie when an old classmate, who's now a beautiful woman, seems to be more interested in Charlie.

After an earthquake hits, Judith's house is damaged and she needs a place to stay. So Alan decides to invite her to stay with him and Charlie, without getting Charlie's permission. Charlie isn't happy with this, but accepts it. Alan becomes jealous when Judith goes on a date, and asks Charlie to find him a date, so that he can show Judith that he dates as well.

The brothers throw out their mother, after she insults the way Alan is raising Jake. When Alan and Charlie ignore her phone calls, to get their attention she ends up in the hospital. When Alan and Charlie show up at the hospital they aren't sure if she's faking, and try to call her bluff.

Alan starts to worry about a medical procedure that he is facing, and to get his mind off it, Charlie suggests they go to Las Vegas.

When Judith decides to take a vacation, the brothers have to take care of Jake during the week. Alan finds it challenging, and even forgets to pick up Jake from soccer practice. When Alan finds out that he has to go to the I.R.S. because they're auditing him, he forces Charlie to take care of Jake, and Charlie doesn't do any better then Alan.

After Charlie has back pain, Alan decides to take him to the Hospital. While there Charlie can't stop hitting on the doctor who is examining him. The only problem is that he has a history with her that he can't remember. Berta is feed up with Jake's inability to use the bathroom properly, so she decides to make him clean it until he learns.

Charlie is invited to a party hosted by a gay ad-executive named Eric, so Charlie asks Alan to pretend that he's his life partner. While at the party, Charlie meets Eric's ex-wife Pamela, and tries to sleep with her without Eric finding out.

After Charlie takes Alan to an eye doctor, they end up at cafe where they bump into Charlie's ex-girlfriend, Sherri. While there Alan shows an interest in Sherri, and decides to ask her out. The problem is that Alan can't get over Sherri's relationship with Charlie.

Rose tries to help the brothers sort out their feelings, when Charlie and Alan take their personal frustrations out on each other.

Evelyn reads in the obituaries that her second husband, Harry has died. They all attend the funeral, including Jake who is excited at the opportunity of seeing a ""dead guy"". Charlie is excited by the opportunity of a newly single widow, and Alan is just happy to pay his respects to Harry.

Evelyn buys Alan a new Sports car causing Charlie to claim that his brother has sold his soul to the Devil. The next day, Evelyn extracts payment by insisting that Alan go on a blind, double date with her, her new beau and his daughter. At the restaurant, Alan learns that his mother and boyfriend will not be able to join them because there was a mixup between his heart medication and Viagra and she didn't want to ""waste it"". As a result, Alan is left to deal with the daughter, who is on a weekend pass from a rehab center and still has some loose screws. Alan eventually gets her back to the beach house only to have her drive off in his new sports car and become the object of a televised high-speed car chase.

Evelyn demands Jake spend a night at her place when she finds out he spent Spring Break with Judith's parents. Neither Alan nor Charlie are keen on the idea, but going to a bar after dropping off Jake quickly erases their concerns.

Charlie unknowingly sleeps with an older man's trophy wife while Jake has to read a paper to his class.

After falling off the roof, Alan needs Charlie's help in looking after Jake, which interferes with Charlie's social life.

Jake gets suspended from school after drawing an offensive picture of a girl in his class that has large breasts. Meanwhile, Charlie is asked to watch over Alan's chiropractic office after pulling an all-nighter.

Alan has been dating a lot, and Charlie soon finds out that it has been one woman - his ex-wife, Judith. He tries to stop Alan, and even brings Rose, Evelyn and Berta to interfere - but Alan ignores them all.

Berta causes tension between Charlie and Alan, when she temporarily moves in with them

Charlie learns he can't be in a long-lasting relationship, becuase of unresolved issues he has with his mother. Jake asks Charlie for advice about a girl at school.

Ignoring Alan's warnings, Charlie continues to date Isabella until she threatens to put a curse on his manhood.

Charlie wakes up with Rose the morning after her birthday party. Her irate father comes to ask Charlie about what the future holds for him and Rose, but the unexpected happens when Evelyn shows up.

Charlie tricks Jake into taking ballet lessons, so he can get close to the teacher.

One of Charlie's elderly neighbors tries to seduce Alan, while Charlie tries to stop Jake from giving money to a televangelist.

Charlie helps Alan with his obsession of always having to get approval from the women in his life.

Alan starts dating a woman with a Martha Stewart complex. Before long she's running the house with an obsession for perfection.

Charlie sees a therapist to learn how to deal with Alan's emotional insecurities.

Charlie finds himself in a relationship that is not based on sex.

Charlie arranges a romantic date with Mia in the hopes of consummating their relationship. Alan begins to date Charlie's most recent ex-girlfriend.

Charlie has trouble keeping up with Mia's healthy lifestyle, so he begins to sneak beers, cigars, and burgers behind her back. When Mia finds out what he was doing, Charlie has to decide if he is truly in love with her or just whipped.

Alan has trouble deciding if he should bring his younger girlfriend to Jake's birthday party to meet his mom and his ex-wife. Rose tries to get her boyfriend to act more like Charlie.

Charlie is nominated for an advertising award, but he decides to boycott it because his arch nemesis always wins. The rest of his family tries to trick him into going. Rose is having relationship problems with Gordon and seeks help from Charlie.

Alan starts to have financial problems when he starts paying for his girlfriend's bills, so Charlie tries to get him to break up with her. Meanwhile, Judith is after Alan because he is late in paying his alimony check.

Charlie is surprised to find out that Kandi has been living with them for the last three weeks. Alan is having a tough time helping Kandi earn a living. Charlie has lost his sense because of the dry-spell he is going through.

Alan tries to win Kandi back. Meanwhile, Charlie starts to sleep with her mom, Mandi, and Judith gets set up with her father, Andy.

Jake’s teacher has a meeting with Alan and Judith to discuss the lack of interest Jake has at school. Alan starts to fall for Francine, in a platonic way, because he is tired of the lack of intelligent communication he has with Kandi. Charlie helps Jake audition for his school musical.

A girl from Jake’s school invites him to his first boy-girl party. Charlie and Alan help him get ready for it by giving him advice. Alan and Charlie get nostalgic and remember their first boy-girl party.

Mia comes back to town with her dance troupe and invites Charlie to her performance. At first, he decides not to go and tries to convince Alan that he no longer has feelings for her. He goes to the see the performance and Mia explains that she wants some of Charlie’s sperm. Charlie responds by asking Mia for something.

Charlie and Mia start making their wedding arrangements. Things begin to fall apart when their two families meet each other. They eventually decide on a small ceremony in Las Vegas.

Charlie returns to his bachelor lifestyle after Alan moves out of the house. Alan suffers a breakdown after his divorce from Kandi.

Charlie finally tells Alan that he didn't marry Mia because she wanted Alan and Jake to move out of the house, but Alan finds a hole in his logic. Charlie and Alan deal with a noisy neighbor who constantly sings all the time, who happens to be Steven Tyler.

Charlie tries to surf to impress Dottie, a beautiful woman he just met, but after he nearly drowns he is convinced that he saw his late father.

Alan tries to hire his ex-wife's lawyer to help him win custody over the dog he and Kandi shared.

Alan is overjoyed by the prospect of Judith remarrying, as he would no longer have to pay alimony. Alan gets Charlie to help him when it looks like the marriage maybe derailed due to Jake’s dislike of his mother’s fiancé.

Charlie is dating a woman whose personality and life are like his mother’s.

Berta's daughter, Naomi is pregnant and Berta drags Charlie with her when she confronts the baby’s father. Alan reveals a secret fetish.

Alan suffers from insomnia. He visits his psychiatrist, who reveals that the cause of Alan's sleepless nights is his jealousy towards Charlie, and his inability to glide through life.

Charlie gets tired of Alan's mooching and reaches the breaking point during the brothers' double date. Jake is left home alone for the first time.

Worrying Charlie may get rid of one of them, Berta and Lydia fight over him. Meanwhile, Kandi does everything she can to stop Alan from selling their condo.

Charlie's friends and family put a crimp in his plan for a romantic Christmas Eve date. When Evelyn sees who the date is, she goes to great lengths to force a wedge between them.

Berta discovers that Alan has been dating her daughter Naomi.

Jake shares that he has heard his mother having sex with her fiancée, Herb; this revelation brings up a repressed memory for Charlie. This leads Charlie to seek help from Rose.

Charlie sets Alan up with their new neighbour. But he gets jealous when the two form a bond.

Rose is moving to London, and Charlie is surprised by his reaction to the news. Alan lies to a woman he met online.

Charlie's young, hot girlfriend takes him to a new club. She invites Alan to meet one of her friends but the men are shocked to learn that they are considered as being "old".

After Evelyn tells Alan and Charlie how she feels about there being no mourners at her friend’s funeral, the boys share their feelings that this could also be the case at her funeral. Evelyn tries to prove them wrong by introducing them to a couple she help adopt a boy from China. The boys return fire by inviting the young man to a play date with Jake.

Alan tries to bond with Jake when he realizes that his childhood is almost over. Kandi pursues a career in acting.

Charlie takes a liking to Myra, the witty sister of Judith's fiancé, Herb.

Alan looks forward to Judith's wedding, while Charlie and Myra continue their romance.

Alan and Charlie re-examine their sexual identities after Alan befriends Greg, a gay man. Meanwhile, Jake has a crush on Greg's daughter.

Jake gets lucky after Charlie takes him to the racetrack. Meanwhile, Alan has a difficult time at the DMV.

Charlie is shocked when the handyman working on his house beats him out for Chloe's affections. Alan has no sympathy for Charlie’s distress.

Evelyn's boyfriend, Teddy, invites Alan and Charlie to go with him to Las Vegas on his private jet. The boys confront their individual 'daddy issues'

Jake is getting ready to start a new school as he graduates to Junior High. Alan and Charlie take him school shopping and find themselves in trouble.

Charlie acts strange after spending an evening with his mother, and a woman Alan slept with behaves oddly the next morning.

Alan convinces Charlie that he needs to date more respectable women and sets him up with a judge. The two double date and their waitress happens to be one of Charlie’s ex-girlfriends. Charlie's date backfires the following morning, when he ends up in court in front of the judge.

Charlie and Linda get closer to consummating their relationship, but Charlie has trouble focusing when he begins to see Rose's face everywhere he turns.

Charlie has to come up with ways to keep his girlfriend's 4-year-old amused; Alan becomes a test subject.

Charlie's girlfriend is embrassed to go out in public with him. Meanwhile, Jake sneaks out to attend a concert.

After Alan and Charlie have a fight about Alan's role in the house. Alan packs Jake up and moves in with his mother.

Charlie writes a children’s song and finds success as Charlie Waffles. The children love him and the mothers seem to as well. Charlie's new found fame irritates Alan.

Charlie fights his attraction for Teddy's daughter.

Alan finds out that Charlie stole his girlfriend and works on a plan to get back at Charlie, even though this happened when they were in high school.

When Alan finds himself wanting to break up with a woman, Charlie offers his expertise.

Rose returns from England, and plays nurse rather oddly for an ill Charlie.

Alan finds out some surprising information about Judith's sex life when he decides to go on a date with one of her friends.

Charlie double-dates with Jake and fixes Alan up with a hooker.

Alan feels Charlie is unable to control his womanizing ways.

Alan makes wedding plans for Evelyn and Teddy, while Charlie figures out how to get more acquainted with his future step-sister.

CSIs investigate a death at Charlie's house.

Charlie's attracted to an older self-help author. Alan and Jake clash over a project for school.

When Charlie meets Angie's soon to be daughter-in-law, he realizes it's not for the first time.

In the 6th season opener, Charlie runs into an ex-girlfriend and a child who bears a striking resemblance to Charlie.

Charlie borrowed money from Alan and on the day he is supposed to pay him back, Alan goes to ask Charlie for the money. He again finds Charlie in bed with a beautiful woman. After Charlie shoos him out and assures him he'll get the money for him later that day, the woman asks if Charlie is really out of cash and Charlie tells her not to worry, that he has plenty of hooker money.

Alan, Jake, and Charlie all decide to try new things: Alan is dating more than one woman, Charlie learns to cook, and Jake experiments with beer.

Alan is sure that things will turn bad when Charlie starts dating his receptionist.

Charlie tries to help Jake's former teacher, who became a stripper after dating him, but things go from bad to worse when she has a religious conversion.

When Judith kicks Herb to the curb, Alan comes knocking; Jake is sent to stay with a less-than-willing Charlie for three months during Judith's meltdown.

Alan tries to escape Judith's grasp as Charlie and Herb go on the prowl to pick up women. They later end up going back to Herb's hotel room with two prostitutes, where Herb declares his love for Judith and races over to win her back.

Charlie's new girlfriend Chelsea asks him to spend the night at her place, which puts Charlie well outside of his comfort zone, while Alan tries to enforce a punishment on Jake initiated by Judith for mooning a group of girls.

Charlie finds himself in an uncomfortable position when Jake takes off with the daughter of a former NFL player. Charlie's Mercedes proves a boon to Alan's love life.

Evelyn offers to pay for Jake's college education, and Alan becomes listless because he has no compelling reason to work anymore, while Jake discovers a hidden talent in the culinary arts that may allow him to bypass college altogether.

Charlie finds himself re-examining his wild ways when an old friend dies and begins to feel that his time on Earth may be drawing to a close.

Charlie and Jake fight for the affections of a waitress, while Alan fights sexual tension with his receptionist.

Judith is pregnant with a baby girl and Alan is convinced he is the father.

Melissa doesn't think Alan's family appreciates him, so she asks him to move in with her and her mom.

Charlie ends up in couples counseling.

Charlie has to remove a half-naked woman from his bedroom before Chelsea arrives.

Charlie's admission that he's in love with Chelsea gets a surprising reaction from her

Chelsea's illness gives Charlie a chance to prove he can take care of her, but also yearning to run away from the situation.

After Chelsea discovers a nude picture of another woman on Charlie's cell phone, he blows off steam by going out for a night of drinking with Alan, Herb and his neighbor.

Charlie's desperate to make sure Chelsea and Evelyn don't befriend each other following their first meeting.

Chelsea is asked by Alan to arrange a blind date between he and her new friend, unaware that her new friend is Rose.

Charlie mourns the loss of his bachelor pad as he reluctantly allows Chelsea to move in. Meanwhile, Alan discovers there is no longer much space left in the house for him.

Alan and Chelsea become best buds, and Charlie decides to take advantage of the situation.

Charlie starts to question his relationship with Chelsea when he hears that Mia is back in town. Meanwhile, Judith goes into labor and Charlie, Alan and Herb rush her to the hospital, on the sixth season finale.

Charlie must make a difficult decision about his future and with which woman he wants to spend his life: Chelsea or Mia.

When Chelsea convinces Charlie to let Alan's new girlfriend, Melissa, move in, the girls end up taking over Charlie's house.

Alan ends up playing maid to Judith's new baby as well as his former mother-in-law. Meanwhile, Jake uses an incriminating photo to blackmail Charlie.

Alan starts working for Evelyn as Charlie works to fix the relationship between Chelsea and Jake.

Jake stops at nothing to get away from Charlie and Alan, after they embarrass him out in public.

Alan's advice to Chelsea that she get breast-reduction surgery is not met with enthusiasm by Charlie, who kicks him out, but staying with Evelyn has its own challenges.

Alan and Charlie are shocked when they wake up next to a strange woman, and try to find out what happened.

While overcoming a bad break-up, Chelsea invites her beautiful college roommate to stay at the house.

While Alan struggles to cure his baldness, Charlie deals with the problem that he can't satisfy Chelsea.

Chelsea wants Charlie to take dancing lessons for the wedding, when Charlie uncovers the truth that Chelsea has been lying about her finances.

Jake is taught the art of infidelity by Charlie, while Celeste is away for Christmas.

Jake hopes to win back Celeste by writing her love songs. Alan and Herb hope to keep Judith from finding out they've become friends.

Charlie opts to have a colonoscopy in order to avoid going on a trip with Chelsea to see her parents. However, when he returns home, he finds her parents at his house.

Charlie suspects Chelsea likes the lawyer representing Alan after his arrest for a bar fight.

Chelsea and Charlie's relationship is at risk when Charlie's jealousy comes between them.

Charlie runs off to Vegas and returns with a new wife, but she's not Chelsea.

Charlie and Chelsea have a post-breakup one-night stand.

Charlie has a return engagement with Chelsea's best friend, while Alan has an unexpected effect on a new female patient.

Alan is torn between the bad influence of Jake's new friend and the hotness of his mother.

Alan tries for an intimate night at a hotel with his new girlfriend, while Charlie takes a different approach to obtain the "girlfriend experience"

Charlie is visited by the ghosts of his ex-girlfriends while Alan and Jake are on a road trip.

Charlie is miffed over Alan's planned attendance of Chelsea's birthday party and suffers the indignity of having Jake chauffer him around following a license suspension.

When Jake finds out that Alan has been dating Eldridge's mom, he packs up and heads to Judith and Herb's. Meanwhile, Charlie decides it's time to cut back on boozing.

Charlie is willing to do anything for Alan to accept Lyndsey's offer to move in with her.

After moving in with Lyndsey, Alan continues to have a rendezvous with Melissa at Charlie's house.

Lyndsey and Eldridge move into Charlie's house after their home burns down.

Alan pretends to be Charlie when he goes out on the town; Charlie sneaks off for cosmetic surgery.

Charlie has difficulty dealing with dating a slightly older woman.

Charlie's girlfriend gets fed up with his stalker, Rose.

Charlie and Alan try to set up Evelyn with Russell the pharmacist.

When Berta takes a couple of days off, Charlie falls for her replacement. Meanwhile, Alan believes he's being stalked by Lyndsey's ex-husband.

When Charlie's ex-girlfriend Courtney is released from prison, he treats her to the good life despite her having been in prison for conning him.

Alan goes to great lengths to be able to get Lyndsey a nice birthday present.

Depressed after his breakup from Courtney (Jenny McCarthy), Charlie goes to see his psychiatrist (Jane Lynch).

Alan feels paranoid when Lyndsey becomes friendly with Charlie.

Obsessed and believing her to be married, Charlie starts stalking Rose. Jake and Eldridge start taping themselves doing Jackass-style stunts.

While Charlie and Rose carry on their "affair," Alan's chiropractic business turns into a Ponzi scheme.

Rose and Alan discover each other's secrets. Meanwhile, Charlie's desperate to get some time alone with Rose.

Alan and Jake meet Walden Schmidt, a broken-hearted billionaire.

Walden deals with his ex-wife, Bridget.

Alan prepares Walden for a date with Bridget, while Jake decides to emulate Walden and drop out of school.

Walden goes looking for Mrs. Right while Alan has an opportunity to reconcile with Lyndsey.

Alan has trouble accepting Lyndsey's seedy movie past, and Walden tries to cheer him up by throwing a party.

Walden receives divorce papers from Bridget, but forgets his depression when he meets a girl who looks eerily like her.

Jake has a crush on his chemistry tutor, who has a crush on Walden. Meanwhile, Alan obsesses over the journal his brother left him in his will.

When Walden begins redecorating the beach house, Alan becomes overly emotional.

Upon his release from the hospital, Alan is met with a slew of challenges that test his ability to cope.

Walden hits it off with a British babe, but neither of them is sure he's ready to re-enter the dating world.

Walden is trying his best to impress his new love interest when Bridget reappears in his life.

Walden's mother arrives and Alan is smitten with her, even as she reveals a secret about Walden's past that sends him into a downward spiral.

Walden’s ex-wife and mother try to take control of his company, so he turns to Alan for help.

Zoey tries to convince Walden to cut his hair and shave; Alan and Lyndsey revive their relationship.

Walden tries to loosen Zooey up by sharing some of Berta's special brownies.

Strained relationships and girl-fighting result when a huge storm traps Walden, Alan, Zoey and Lyndsey in the house on Valentine's Day.

Walden and Zoey's relationship suffers after they share a near-death experience. Meanwhile, Alan wonders if Lyndsey has a drinking problem.

Walden's ex-business partner shows up at the beach house looking to make peace.

Alan and Lyndsey introduce their mothers. Jake and Eldridge get a ride from Walden to a party.

Walden breaks the news to Zoey that he is going into business with his ex-wife. Alan and Lyndsey try to cope with their mom's relationship.

Walden's commitment is tested when Zoey and her daughter come to live with him. Meanwhile, Alan gets more than he bargained for when he moves in with Lyndsey

Charlie's ghost pays a visit to Alan after he suffers a minor heart attack.

Alan is showered with love and affection upon returning from the hospital, but Zoey isn’t so sure it’s deserved.

Jake is pressured to make a decision about his future.

Walden plans a big surprise for Zoey's birthday.

Zoey and Walden break up, causing Walden to experience a breakdown.

Alan and Lyndsey decide to spice things up in the bedroom.

Walden starts to feel his age when a friend's daughter comes to town.

Despite Alan's warnings, Walden starts dating Rose.

Walden must choose between Zoey and Rose.

When Walden gets tired of the complications that come with a traditional relationship, he hires an actress to be his girlfriend; Jake plans a rendezvous with Missi (Miley Cyrus) at the beach house.

Alan feels reluctant to make a commitment to Lyndsey, but an unexpected source inspires him; Walden enjoys being the boy-toy of a wealthy older woman.

Alans famous ex-wife, Kandi, wants to reconcile; when Berta isn't interested in celebrating her birthday, Walden tries to make her day special.

Alan helps Walden create a new identity so he can avoid women who are only interested in his money.

Walden juggles his two identities; Alan ends up alone on Christmas.

Alan invests Walden's money in Kate's fashion line; leading a double life takes its toll on Walden.

Alan and Walden go to Kate's fashion show in New York so Walden can reveal the truth about his identity.

Alan is faced with relationship trouble when he does not give Lyndsey a key to the beach house; Walden, Alan, Herb and Billy commiserate about relationships.

When Jake brings his 36-year-old girlfriend home for a visit, Alan is concerned; Walden tries to hide something from Alan.

Depressed on Valentine's Day, Walden tries to talk Kate into giving him another chance; Alan's holiday plans go south.

When Walden runs into his ex and they start talking about getting back together, Alan worries that she is not good enough.

After a fight with Walden, Alan decides to move in with Herb.

Alan and Walden end up partying too hard as they try to cheer up Herb.

Walden and Alan are caught in the crossfire when Jake cheats on his girlfriend (Jaime Pressly) with her 18-year-old daughter.

Alan has a difficult time coping when Lyndsey breaks up with him.

With encouragement from Walden, Alan decides to update his look; Alan is faced with a moral dilemma when he attracts a married woman.

Walden dates an attractive 22-year-old (Hilary Duff), but ends up being more interested in her grandmother (Marilu Henner); Jake and Alan go on a trip.

Charlie's 25-year-old daughter arrives at the beach house, hoping to get to know her family.

Jenny moves in with Evelyn and her wealthy boyfriend, Marty (Carl Reiner).

Walden and Alan think it may be time for Berta to retire when she injures her back at work. When they suggest her retiring, she grows offended, and as the conversation progresses she quits. Walden and Alan then try different maids, with little success.

Alan and Lyndsey's illicit relationship becomes jeopardized when one of Lyndsey's man-hunting friends, Stephanie (Jennifer Aspen), asks if they are back together. The two staunchly deny it, then Lyndsey insists that Alan make a date with Stephanie so that she will believe their lie. Alan meets her for an uncomfortable date, which nevertheless leads to sex, causing Lyndsey to get mad and leave Alan again.

Alan tries to find out what Lyndsey's boyfriend has over him; Walden helps Jenny pursue her acting career.

When Alan learns Walden knows Lynda Carter, he asks him to set him up on a date with her. Against his better judgment, Walden agrees to invite her to the house for dinner.

Walden and Alan find themselves on dates with two ideal women until Lyndsey's jealousy throws a wrench in their evening.

Alan and Lyndsey’s illicit affair puts Walden in danger, forcing him to accept Rose’s help.

Walden goes on a date with an accident-prone model; Alan's date reveals surprising personal information about herself to him.

Jake sends Alan a Japanese delicacy; the house comes alive with questionable Christmas lyrics.

Walden joins his beautiful former employee on a brilliant new project. Meanwhile, Alan advises Jenny to open up to her girlfriend or risk losing her.

Lyndsey's boyfriend sets Alan up on a date; Walden wants to help Nicole with her project so she will have time to date him.

Marty Pepper (Carl Reiner) proposes to Evelyn; Alan and Walden plan a bachelor party for Marty.

Alan finds out that Lyndsey broke up with Larry without telling him; Walden tries to prove he is a man's man.

Alan asks Lyndsey to choose between him and Larry; Jenny worries that she and Brooke are growing apart.

Walden thinks his girlfriend is cheating on him; Alan starts dating Larry's sister, Gretchen (Kimberly Williams-Paisley).

Lyndsey finds out about Alan's relationship with Gretchen; Walden has a difficult time telling Barry to find his own place.

Walden gets an invitation to his ex-girlfriend's boutique opening. Meanwhile, Gretchen wants to spend more time at Alan's (a.k.a. Jeff Strongman) house.

After reconnecting with Kate, Walden becomes convinced she is the one for him -- until he meets a woman named Vivian (Mila Kunis).

Alan finds an opportunity to make money; Walden addresses his co-dependency issues.

Alan's girlfriend, Gretchen, insists he confess his true identity to Larry. Meanwhile, Walden goes on a road trip with Jenny and Barry to see his first car.

Alan must face the consequences after revealing his identity to Larry.

After a health scare on Halloween, Walden decides he needs to change his life.

Alan has second thoughts about getting married after he's asked to sign a pre-nup.

Alan and Walden have a meeting with an adoption social worker that hinges on them being convincing as a loving couple. Lyndsey returns after 60 days in rehab.

A birth mother considers having Walden and Alan adopt her baby.

Walden becomes a foster parent to a 6-year-old boy, but worries about himself when they don't hit it off like he hoped.

Alan breaks Walden's rules when he realizes that Louis thinks he's cool, and he wants it to stay that way.

Alan and Walden befriend three moms at a kids’ gym, but things get complicated when Walden becomes attracted to one of them. Alan goes out for a girls’ night with a group of moms.

Alan and Walden attempt to convince Louis that Santa Claus is real.

Walden discovers how challenging it is to be intimate with women when his foster son, Louis, is in the house. Also, Herb asks Alan if he can go on a date with Lyndsey.

Alan takes it upon himself to help Walden keep Louis after the social worker discovers he and Walden are not really a gay couple.

Walden joins a group for adoptive fathers, and finds it to be a nice escape from Alan.

When Alan breaks up with their social worker to get back together with Lyndsey, Walden worries it will affect Louis’ adoption.

Walden fears if he breaks up with Ms. McMartin, it will jeopardize his adoption of Louis. Also, Alan hesitates when Lyndsey asks him to move in with her.

After they sign their divorce papers, Walden offers Alan the gift of his choice, but when Alan chooses something selfish and impractical, it puts his relationship with Lyndsey on the line.

Charlie Harper is alive. Or is he?

Charlie Harper is alive. Or is he?