In present day, Celeste and Jesse still get along well. Celeste is a successful trend analyzer and runs her own media company with her partner, Scott (Elijah Wood). Celeste's media company has just signed Riley (Emma Roberts), a teen pop-star whom Celeste does not respect and openly bashes during a T.V. interview. Jesse on the other hand is an unemployed artist who seems to be in no hurry to find employment. One night, they have dinner with their mutual best friends, Beth (Ari Graynor) and Tucker (Eric Christian Olsen), who are engaged. During dinner, while Celeste and Jesse look at the menu and speak with German accents to each other, Beth becomes increasingly annoyed and confronts them about their abnormal relationship. She expresses that it's not normal for them to spend everyday together like nothing is wrong. It is then revealed that they have been separated for 6 months and in the process of divorce. Celeste and Jesse tell Beth that it's better this way because when they were together, they fought all the time and Beth and Tucker get caught in the middle. Angry, Beth storms off, with Tucker following her, having the same feelings. In the car ride home, Celeste and Jesse discuss whether they feel it's weird that they spend so much together, and they assure each other it's not weird because they are each other's best friend.
One day, Jesse is out with his friend Skillz (Will McCormack) who feels that Jesse should start dating other women. Jesse informs him that he's hoping for Celeste to "come back around". It is obvious that Jesse is still in-love with Celeste and is hoping she will change her mind about the divorce. While at work, Scott is questioning Celeste about whether she made the right decision divorcing Jesse and if she's truly over him, she would also begin dating. One night, Celeste invites Jesse over to help her put together an Ikea dresser. They become frustrated from trying to built the drawer and they instead get drunk on wine and spend the night together. They both wake up and Celeste instantly regrets what happened the night before and this upsets Jesse and he storms out angry because he thought the night together meant Celeste had finally "came back around".
Celeste goes on a business trip and repeatedly tries to get a hold of Jesse. Jesse is then seen on a date with Veronica (Rebecca Dayan), a woman Skillz set him up with 3 months ago, but never called back after the first date. Celeste returns home after two weeks and Jesse comes over to speak to her. Jesse informs her that he is going to have a baby with Veronica, a woman she never knew he went out with 3 months ago, and wants to try to make things work for the sake of the baby. Celeste becomes disturbed by this and asks to be excused while she goes to the bathroom and becomes upset. She expresses her concern to Beth who questions about her having second thoughts with the divorce. Celeste assures Beth that she's not having second thoughts and says she's going on a date.
Celeste goes on a date with Max (Rich Sommer). During the date, they run into Jesse. This makes Celeste feel awkward and ask Max to leave. Max says he's not going to leave and meets Jesse, whom he finds is a cool guy. After the date, Celeste ask him when he'd like to go out again, but Max turns her down and tell her that she's not ready and she should take her time, just like he did when he was going through a divorce. Her second date is with Rupert (Rafi Gavron), a model/actor who is young and hot. He sings to her during their date and she abruptly leaves, telling him she left a candle lit at home. Celeste is clearly uncomfortable with his singing and age. Her third date is with a photographer whom she is a big fan of. They initially hit it off and go back to the hotel and make-out. During their make-out session, he begins to masturbate while on top of her. This shocks her and she slowly creeps away from under him and leaves, but he continues to masturbate. In the mean time, Jesse is becoming closer to Veronica and even becomes a vegan. Jesse invites Celeste out for lunch at a vegan restaurant to confront her about their divorce papers. He informs Celeste that she needs to sign the papers because Veronica is not a U.S. citizen and they must get married for her to stay. This upsets Celeste and she storms out stating she's busy because she has a job, unlike some people and says she'll sign the papers when she has the time. As time passes, Celeste realizes that her decision to divorce Jesse was impulsive and selfish and starts to realize she still loves him and wants to be with him. Celeste ask Jesse to meet her at a bar where she express her interest in trying again and that she'll try harder and do better. Jesse becomes upset and leaves. Celeste chases him outside and they begin to argue. Celeste calls Jesse a coward and Jesse tells her she'll be alone forever. The argument ends with Celeste telling Jesse never to call her again and Jesse assuring her that she does not have to worry.
Celeste becomes increasingly depressed and begins to drink and smoke weed excessively. In the process, she begins to have a relationship with Paul (Chris Messina), who tries to pick her up after Yoga earlier in the film. She initially turns him down, but begins to warm up to him after she runs into him at a party. During Beth and Tucker's bridal party, Celeste becomes drunk and passes out on a floaty in the pool, with everyone staring at her. After the bridal party, she gets a call from Riley who ask her to come over. Celeste believes that Riley is angry over the logo she designed for her that unintentionally resembles a penis with balls going into a butt. This logo sparks controversy with fans. However, Riley reveals that she actually likes the logo because she believes it speaks to her gay fan base. Celeste thinks that Riley could be the next Lady Gaga because of this. Celeste arrives at Riley's house to find her in tears. Riley reveals that she has had a secret boyfriend, who she discovered has been cheating on her. They begin to bond over the common experience of heartbreak and slowly become friends. Later, Celeste runs into Rupert while walking with Riley and introduces them.
At Beth and Tucker's wedding, Celeste makes a toast. She tells the newlyweds to appreciate each other, to be patient, and to try harder, like she should have. This speech touches Jesse, and he thanks Celeste. They are able to reconcile and become friends again.
Later, on a karaoke date, Celeste informs Paul that she cannot continue to date him because of her divorce, which she feels she must go through alone. He tells her to call him when she is ready. We then see Celeste and Jesse finally signing their divorce papers and laughing at each other's inside joke. Their lawyers look on, confused by their laughter. Celeste wishes Jesse well. She finally asks Jesse if he loves Veronica, to which he responds that he does. Celeste tells him to keep fighting for it.
In the final scene, Celeste calls Paul while driving. She gets his voicemail, so she leaves a message stating she's ready — to beat him at Scrabble.