Divorced office worker Henry Willows is content in his uneventful life, one of his few domestic contacts being Enid, who comes in to clean for him. However his ordered existence is shattered when his seventeen year old son Matthew arrives on his door-step, having previously lived with Henry's ex-wife. Matthew claims that he was fed up at his mother's house and was keen to see his father again. A call to the ex-wife uncovers another story. Matthew was thrown out and told to move in with his father. Henry is about to find out why.

Henry and Matthew's differences in age and taste are constant and comic irritants in their daily confrontations, but they rise to new levels when the subject of education is raised and they must choose a school for Matthew.

When Matthew brings a girlfriend home, the cleaning lady finds incriminating evidence in his bedroom.

When Henry's next door neighbour's son returns from college, comparisons between Matthew and the student are inevitable. But while the neighbour boy might look to be industrious, considerate, well-mannered and a great sportsman, Matthew knows the truth.

Wine is chilling, candlesticks are on the table and Henry has shaved. Who is coming to dinner? Matthew attempts to find out.

As most young people are, Matthew is desperate for money, but his father refuses to invest in his future unless he finds more suitable employment.

It's Henry's wedding anniversary, but after seven years of separation there is nothing to celebrate, so he goes to the club. While he is out, Matthew welcomes a special guest into his father's home.

Henry and Matthew's relationship is strained further when Matthew becomes an animal rights activist.

Henry comes home to find the house full of Matthew's friends—more of an orgy than a party, says Henry—but rather than throw them all out, he joins in with hilarious results.

Matthew inherits a large sum of money, but finds it impossible to hold on to. Matthew opens a bank account, but how long can he withstand the temptation of ATMs and credit cards?

Henry is stunned to find Matthew wearing makeup, and even more stunned when he finds out Matthew wants to become an actor. Matthew has joined the college drama group to play Othello, with a married woman as his Desdemona. Henry is horrified at the result.

Henry suffers every father's nightmare—teaching his son to drive. Inevitably, Henry's pristine new car begins to show signs of stress.

Prospective candidate Henry is opposed by an attractive woman in the election, creating a quandary for first-time voter Matthew.

Matthew's sister Julie decides to stay, but Henry and Matthew soon find that three's a crowd.