Before a night out, Les brings his girlfriend Carol back to his family's flat. Watching part of a television programme about nudists, Carol says that she could not do what they do. Les argues that everybody is born naked and that people are naked under their clothes.

Les's sister Yvonne comes in. Les says that Carol shouldn't smoke. He wants to have some tea, although he is going out for supper with Carol. Yvonne makes Les's tea, warming up their mother's cooking: Les's mother usually cooks his meals. His mother and stepfather Arthur are working late and won't be home until nine; Les wants to leave at half past eight. Les asks about some of Yvonne's failed relationships. Yvonne realises that Carol and Les have been seeing each other for a few weeks now. Yvonne's former husband was bad to her, and left her.

Les eats his tea lying flat on the settee. Les and Vyonne discuss their mother's inadequacies as a cook. Les adds that his mother is ugly and that he doesn't want Carol to meet her. When Les is accused of eating like a pig, he replies that pigs are his favourite animals and are intelligent: they live a life of luxury, don't go to work or the Labour Exchange and have their food brought to them. Yvonne replies that pigs eat horrible food and that we then eat them. Les wants a pig as a pet, and imagines taking one for a walk. Carol tells Les to sit up because he might get indigestion, but Les saw on television that people can eat in any position because swallowing has nothing to do with gravity but is due to throat muscles. Carol recalls from biology lessons that this is called peristalsis.

Yvonne tells Les about a woman she saw at work, whose stomach was bloated because of a false pregnancy. Remembering Les's comments that it was caused by wind and imagining when that wind will escape, Yvonne laughed at the woman when she came in. Les and Yvonne laugh at this. Jimmy, a gay man, hasn't been coming into work, but Yvonne says that he enjoyed his workmates pulling his leg. Carol helps Yvonne to do the washing up. Carol was an only child; Yvonne asks personal questions about why her parents didn't have any more children. Carol's mother had had a couple of miscarriages and had an operation.

Yvonne - nagged by Les to hurry up - gets ready and goes out. Carol complains to Les for not eating at the table or helping with the washing up and argues that nobody is forcing him to behave like an animal. When he tells her to shut up again, she says that she will leave if he does it again: he does and she puts on her coat. She asks him to come to the pub but he insists on waiting until half past eight. She sighs and he ducks, thinking she was going to hit him.

Carol doubts Les had treated his previous girlfriends like this. He makes a joke about usually tying them up, but then admits that he's never had a girlfriend or, apparently, had sex. She wonders whether this is why he had failed to try anything on with her. Because she was his first girlfriend, he didn't want to spoil it. He says that sex is everywhere, in newspapers, on television and in films, but that it isn't really like that. He remembers finding out about sex through learning about frogs and spawn at school. His stepfather said that was like human sex, so Les thought that was why people went to swimming baths.

Looking round the flat, Carol goes into Les's bedroom. He apologises for his behaviour earlier. She encourages him to play his ukulele, and he sings 'Leaning on a Lamppost'. Carol kisses him.

Yvonne returns home early because her date did not arrive. Upset, she has chosen to walk up seven floors of stairs rather than take the lift. Les asks if Yvonne wants to come to the pub with them, but she doesn't. Les and Carol leave. Yvonne stands in the kitchen.