Early one morning, twelve-year-old Franny Philips reads the book, The Joy of Sex, while sitting at the front window of her home, a townhouse on Manhattan’s West Side in New York City. When she looks out and sees her father, Paul Philips, arriving, she logs the time, 6:05am, in a notebook, which she has done every morning for the last three weeks. Before going back to bed, Franny hides The Joy of Sex on the shelf. She pretends to be asleep as her father tiptoes by her bedroom door. He puts on his pajamas and makes room in the bed next to his wife, Madeleine. After the alarm rings, he wakes Franny. Alone with Madeleine, Paul tells her that he will maintain this crazy routine until he is ready to inform Franny about their upcoming divorce, since he is concerned about how it will affect her. Before leaving for school, Franny gets permission from her mother, who is barely awake, to attend a sleepover on Friday night. During the day, Franny confides in her new friend, Jamie Harris, a preteen boy who has recently transferred to the same school. Being a child of divorced parents, Jamie advises Franny about her father’s unusual behavior, cautioning her not to confront her parents since they are making a big effort to keep their separation a secret. When her mother comes home from work, Franny reminds her about the sleepover at Jamie’s house the next night. Madeleine is taken aback, unaware that the sleepover would be at a boy’s place. She telephones Jamie’s mother, Barbara, who is now married to Simon Peterfreund. Oblivious of the plan, Barbara declares in an unfriendly tone that Jamie will be with his father, Ralph Harris, that weekend per the divorce agreement and abruptly hangs up. Madeleine tries Ralph at his production company, but his secretary, Fiona, informs her that Ralph is shooting on location, but will be back in time for his scheduled weekend with Jamie. On Friday night, Paul anxiously watches as Jamie and Ralph arrive in a Maserati sports car to pick up Franny for the sleepover. Although Paul is nervous about the arrangement, he lets Franny go. Ralph takes the kids and his date, a stewardess, to an Italian restaurant. After dinner, Jamie shows Franny how to play bocce while Ralph cuddles with the stewardess. Franny asks if Jamie is bothered by his father’s flings, but Jamie says that he has become accustomed to it and evaluates the women with letter grades, giving this one a C-. When the group returns to Ralph’s Manhattan apartment, the stewardess becomes possessive and convinces Ralph to drive her home, leaving the kids alone. Jamie changes her grade to a D. Giving a tour of his father’s exotic bachelor pad, Jamie instructs Franny to take off her shoes. She is immediately enchanted by the apartment, which includes a tropical sanctuary with a parrot and piranhas as well as a bedroom furnished with a waterbed, wall-to-wall mirrors and a jukebox. While watching a late movie on television, Franny and Jamie wrestle. Their horseplay leads to a brief kiss, which Franny finds unpleasant because of Jamie’s braces. To prepare herself for her parents’ divorce, Franny asks Jamie about his experience. He relates that his mother and father finally told him what he already knew by taking him to his favorite restaurant, McDonald’s, offering to buy him a dog and declaring their love. Because the place will always remind her about the split, Jamie encourages Franny to choose a restaurant she hates. Franny decides she will pick Chinese. At a meeting to discuss the details of their divorce, Madeleine and Paul compromise until the issue of custody is raised. Madeleine and her attorney, Steve Sloan, reiterate to Paul that Franny needs to be informed about the divorce before any arrangement can be made. Bea, Paul’s attorney, advises the parents to take their daughter some place she likes. At a Chinese restaurant, Paul is surprised by Franny’s dining selection since she has always hated Chinese food. As Franny sits quietly, her parents compete for her attention. Calmly, Franny interrupts to announce that she knows they are getting a divorce, so they can stop pretending. That evening, Madeleine tries to explain to Franny how the marriage changed. The next morning, Paul assures Franny that everything will be fine when she comes to live with him and says he loves her. Upset, Franny runs down the sidewalk and does not stop until Jamie chases her down. Later, she and Jamie return to Ralph’s bachelor pad, which Franny wishes she could stay at forever. Jamie suggests spending the weekend while his father is gone. Instead of telling her mother the real plan, Franny fibs and asks if she can visit Jamie and the Peterfreunds at their country house. In her plea, Franny reminds her mother that she does not need to seek the permission of her father anymore. That weekend, Franny telephones her mother from Ralph’s bachelor pad to report that she is doing fine at the Peterfreunds’ country house in Westport, Connecticut, and embellishes the lie by saying that Jamie’s mom is cooking dinner. When Madeleine asks for a phone number, Franny gives her 687-4321, the actual number to Ralph’s apartment. Madeleine adds the area code 203 for Westport. During the weekend, Jamie shows Franny home movies of his grandfather, which include footage of his smiling parents before their divorce. The kids pretend to be adults by having breakfast in bed and opening a bottle of champagne. Meanwhile, Paul moves his things out of the house. While contemplating the empty spaces left behind, Madeleine finds The Joy of Sex hidden on the bookshelf and later wonders whether Franny’s interest in the book relates to her new friendship with Jamie. Unable to locate Franny at the fake Westport number, Madeleine wakes up the Peterfreunds at their Manhattan residence. They inform her that Jamie is scheduled to be in East Hampton, New York, this weekend, stating further that they do not own a house in Westport. After no one answers at 687-4321, Paul and Madeleine rush to Ralph’s building and meet the Peterfreunds who have arranged for Fiona to unlock the door. When the frantic parents invade the apartment, they find Jamie and Franny taking a bubble bath together. Mayhem occurs as they try to get their kids out the tub and dressed. Unaware of the kids’ scheme, Ralph arrives home. As the adults continue to argue and blame each other, Jamie and Franny sneak out the building. After walking Franny to her house, Jamie mentions that it was the best sleepover he ever had. At the end of the evening, Paul and Madeleine are relieved to find Franny at home in bed. The next morning, Franny realizes that her father spent a full night at the house and questions both parents about the possibility of reuniting. Madeleine does not make any promises, explaining that two people should stay together because it is what they want, not what everyone else wants. Later at school, Franny reassures Jamie that she is doing fine, and he gives her an A grade, as they proceed to the park with their classmates.