In the summer of 1980 in Chicago, Illinois, Danny Martin, a restaurant supply salesman, is engrossed in his friend Bernie Litko’s story about kinky sex in an attractive woman’s apartment, which involved a flak suit, a tape recorder with the sound of bombs dropping, and gasoline splashed on the walls. Danny wants to know if the woman was a professional, but Bernie cannot say for sure. He left just as the firemen arrived, and Danny comments that nobody has normal sex anymore. Later, as the friends play softball in the park, Debbie Sullivan, an art director in an advertising firm, and her friends take turns picking out the most attractive ballplayers. After the game, everyone goes to Mother’s bar, but Debbie is disappointed that her boss, Steve Carlson, the losing pitcher, decides not to go. At Mother’s, Debbie, and her friend, Joan, a kindergarten teacher, watch as their girlfriend, Pat, flirts with Bernie and Danny. Debbie watches Danny from across the room. As she and Joan leave, Danny introduces himself to Debbie. They go back to his apartment, listen to his new stereo, and make love. In the middle of the night, Debbie dresses, and turns down Danny’s offer to drive her home. Back at her apartment, Debbie confesses to Joan that she made love to Danny so quickly because of her intense physical attraction to him. At work, Bernie shares his latest conquest, and then wants to know how Danny fared. Danny describes his evening with Debbie as fun. Bernie heckles Danny for his lack of conversation, but Mr. Favio, the boss, interrupts them. Soon, Danny calls Debbie at work. She claims the previous night was a fluke, but he invites her to meet him for drinks at Mother’s. Meanwhile, Debbie’s boss, Steve Carlson, asks her to lunch, but she has a deadline, and refuses his invitation. Later at Mother’s, Debbie tells Danny she does not plan a repeat of the other night, but she cannot resist and ends up in bed with him. This time they share secrets, and Debbie stays all night. In the following days, they go to ballgames, have lunch, walk along the river and are absent from work. Steve Carlson stops by Debbie’s desk, reads her messages, and realizes she is dating someone. Joan telephones Debbie but cannot reach her, while Bernie leaves messages for Danny, and covers for him at work. One day, Danny confesses to Debbie that he would like to own a restaurant. At work, Danny misses closing a deal with a client, and Mr. Favio threatens to withhold Danny’s commission, but relents at the last minute. Bernie warns Danny to cut down on the amount of telephone calls to Debbie. Joan tells Debbie that if Danny’s telephone calls are becoming infrequent, he must be seeing other people. After an evening of sex with Steve, Debbie says their affair is over. Debbie visits Danny to say hello, but is afraid of appearing too easy. He charms her, and they spend the night together. Later on the train, Bernie asks Danny if Debbie has performed fellatio, but Danny does not answer. Meanwhile, Debbie and Danny decide to live together, and Joan feels hurt and abandoned. The compromises start immediately as the couple decides how to rearrange the furniture, and how to make their lives fit. Danny reassures Debbie that she belongs with him. Back at work, Mr. Favio orders Danny to drop Gus, a longtime client and diner owner, who is late with his payments. When Gus begs Danny to reconsider, Danny returns home drained. He keeps the details of the day from Debbie, who complains that it is important to share the good and bad days, but Danny worries that sharing his problems will make him less attractive. Debbie responds that she does not want to live with a stranger. They work at being more open, but one day, Debbie tells Danny she has tested negative on a pregnancy test, and is disappointed when he is relieved. Back at work, Mr. Favio yells at Danny for keeping Gus as a client. Danny walks out, but later, Bernie tells him that Mr. Favio wants him back at work. Danny returns, but it sours his mood. His unhappiness spills into Thanksgiving. He and Debbie fight about everything: the menu, the division of labor, and the guest list. After the meal, Bernie and Danny watch a football game, while the women gossip in the kitchen. Later, the couple has another fight about Debbie’s messiness, the need for a maid and the fact that Danny did not know about her past affair with her boss, Steve. Debbie leaves, and Joan comforts her, but she later returns to Danny. At the office holiday party, Debbie has to fend off Steve’s advances in the copy room, and explains that she is in love with Danny. However, Danny is not happy when he arrives at Debbie’s office, and sees her and Steve standing together at the elevator. Debbie and Danny share a wordless ride home, and go to bed without making love. Later, they share a quiet New Year’s Eve dinner when Bernie calls, and insists they party at Mother’s. There, Joan’s boyfriend tells her he is going back to his wife. When Debbie asks Danny to help take Joan home, he refuses, and wants her to choose him over her girlfriend. Later, when Debbie returns, Danny is waiting for her in the living room. He tells her that their relationship is not working, and he does not love her anymore. He hopes that she finds what she is looking for, and Debbie moves out. They see other people, but Danny cannot forget about her. He calls Debbie at work, but she does not want to see him. At a St. Patrick’s Day party at Mother’s, they run into each other. When Danny tries to tell Debbie his life is not working without her, she runs into the street. He loves her, but she has moved on, and she tells him to get on with his life. Soon, Danny quits work, and buys Gus’s diner. When Joan tries to get Debbie to attend a relationship workshop with her, Debbie refuses, and accuses Joan of conspiring to break up her relationship with Danny. Joan apologizes, and the friends make up. One day, as Debbie and Joan bicycle in the park, Debbie sees Danny on the ball field. She stops to talk, and they both apologize for ruining their relationship. Somehow, they thought that living together would be different. They decide to meet for dinner while Joan is out of town. When Bernie sees the look on Danny’s face after Debbie leaves, he excuses his friend from the ball game and suggests that Danny spend time with Debbie instead.