In LA in 2003, after an evening of playing poker with another couple, Debbie Dunn and Peter Coleman have sex and spend the night together in her home.Twenty years later, Debbie and Peter are best friends. He has moved to New York City and has become a successful businessman, while she still lives in Los Angeles and works as an accountant at her son Jack's middle school. Debbie calls Peter on his birthday, and they discuss her plans to head to New York soon to complete an accounting program to help her get a better-paying job. Debbie's ex-husband's actress girlfriend, Scarlet, is to watch Jack for the week but flakes when she is offered a role in Vancouver for two weeks. Peter, who has just broken up with his girlfriend and between jobs, offers to go to LA to take care of Jack instead.In California, Peter picks up Jack at school and learns that Jack's classmate, Wade, has stopped being friends with him since Jack could not make the hockey team. Peter also learns the extent of Debbie's overprotective parenting and decides to let Jack loosen up a little. To get Wade to be friends with Jack again, Peter gets tickets for the skybox of a Kings game and encourages Jack to invite Wade and his new friend Evan, but this goes awry when they ignore him.Meanwhile in New York, Debbie attends her accounting classes and meets Peter's ex-girlfriend, Minka, who invites her out for drinks. At the bar, Minka helps her catch the attention of book publisher Theo Martin, and he gets her number. At Peter's apartment, Minka tells Debbie that Peter has written a novel. Debbie, who assumed that Peter told her everything, is shocked. After reading the manuscript, she pretends to be a freelance editor when trying to convince Theo to give it a chance, and he agrees to look over it.Peter starts to get closer to Jack and convinces the hockey coach to let him try out for the team. Pleased, he talks to, Zen, Debbie's neighbor who also basically lives in her garden. Zen tells Peter that he stays around Debbie's house in an attempt to get her to notice him, which reminds Peter of his own feelings for her. Meanwhile, Debbie goes out on another date with Theo, which ends with them having sex at Peter's apartment. Debbie accidentally sets off the apartment's remote camera, leading to Peter witnessing them. Disturbed, he goes to a bar and meets an old girlfriend but cannot bring himself to sleep with her. In a conversation with his and Debbie's mutual friend Alicia, he admits that he is in love with Debbie.On Debbie's last day in New York, she passes her exam and unintentionally discovers Peter's hidden mementos of her, including a poker chip identical to the one she kept from their night together. When Debbie meets with Theo, he informs her that he has gotten her an interview with a major publisher. When he expresses the feelings he has for her, she confesses she thinks she's already fallen for someone else.In Los Angeles, Jack's tryouts go badly, and he ends up injured. Peter calls Debbie, and she is enraged that he endangered her son even though Jack appears to be okay. She rushes to leave and get back home to Jack and tells Peter to be gone by the time she arrives.Peter and Debbie come face-to-face in LAX. After a heated argument, Peter admits that he is in love with Debbie, and they kiss. Six months later, Peter has become a published author and moved in with Debbie. She is an editor at an indie publishing house, and Jack is playing on the hockey team