George Dupler (Gene Hackman), a married man nearing middle age, is demoted after a temper tantrum at work (throwing a chair out of his boss’s window) and reduced to working as the midnight-shift manager of an all-night pharmacy/convenience store.
George’s 18-year-old son, Freddie (Dennis Quaid), is having an affair with an older, married woman, who also happens to be Freddie’s fourth cousin. George advises Freddie to stop the affair before it leads to any trouble, but Freddie declares that he might love her. One night at the store, George finally meets the woman, Cheryl (Barbra Streisand), an untalented singer-songwriter married to a volatile firefighter, Bobby (Kevin Dobson), and she begins to show an interest in him. After a while, the interest is mutual.
George goes to Cheryl’s house to return her cigarette lighter. She offers to show George the paint job Freddie has done in her bedroom. George and Cheryl are about to get intimate, when Freddie comes over to see Cheryl for another tryst. George escapes before Freddie could see him, but Cheryl decides to tell Freddie about the affair she is having with his dad. The next day, when George is trying to sleep, and his wife, Helen (Diane Ladd), is having a French class, Freddie confronts his father, trying to fight him. Helen hears about the affair and George leaves. When she demands a divorce, George agrees.
George ends up quitting his job and leasing a loft where he can pursue his dream of being an inventor. George goes to an anniversary party where everybody he knows is there, including his family, plus Cheryl and Bobby. He realizes Bobby is aware of the affair with his wife. George takes Cheryl away from the party and her husband. Even though Cheryl loves him, she thinks he is too good for her.
Cheryl goes to the fire station where Bobby works to talk to him. Bobby ends up yelling at her and is about to hit her when the fire alarm goes off. He and all of the firemen leave, whereupon we see that it was George who reported the nonexistent fire.
Cheryl moves into George’s place. Freddie has accepted the situation and helps her move in, showing that he and his dad have reconciled.