Short Ending:
It turns out that womanizer Jacob (Ryan Gosling) has fallen in love with Cal's (Steve Carell's) oldest daughter, Hannah (nicknamed "Nana" played by Emma Stone). Cal, who had been trained by Jacob in the art of seducing/objectifying women during his divorce, refuses to accept them as a couple. At his son Robbie's (Jonah Bobo's) eighth grade graduation, his son's speech makes him realize that he still believes in love and proclaims it before Robbie's entire school. Cal accepts Jacob as Hannah's boyfriend and vows to keep trying to win back his wife Emily (Julianne Moore) who seems receptive to his advances.
Long Ending:
This movie follows several stories:
- Cal and Emily - The movie begins with Emily wanting a divorce after she has an affair with David Lindhagen (Kevin Bacon). She and Cal have been dating since they were 15. The two have three kids, Robbie (an 8th grader), Molly (the youngest) and Hannah (whom they refer to only as "Nana," we don't discover that Nana is Hannah until the end). They separate, and Cal meets the wealthy playboy Jacob at a bar. Jacob decides to help Cal become a playboy and regain his manhood, teaching Cal how to objectify and seduce women. Cal is successful, sleeping with nine women in about a month. Meanwhile, Emily tentatively builds a relationship with David Lindhagen. Both Cal and Emily make unsuccessful overtures at various points to reconcile with each other.
- Robbie and Jessica (Analeigh Tipton) - Robbie is in love with his 17-year old babysitter Jessica. Meanwhile, Jessica has a secret crush on Cal. Robbie is inspired by his parent's love and makes grand gestures of love to his "soul mate" Jessica, who continually rebuffs him and pines away for Cal. Her love for Cal is unrequited (and in fact, Cal doesn't learn of her feelings until the end when he is confronted by Jessica's parents after they find nude pictures of Jessica that she had taken to send to him but never did). When Cal's final grand attempt to win back Emily ends in disaster, Robbie decides to give up on ever winning Jessica.
- Jacob and Hannah - Jacob hits on Hannah at a bar and she rejects him. Months later, Hannah realizes that she has wasted her time with her non-committal boyfriend and seeks Jacob out for a one night stand. She forces him to use all his "moves" on her, and they work. In the bedroom, however, they end up finally talking and, instead of having sex, Jacob falls to sleep in Hannah's arms after he reveals his inner-most feelings to her. Jacob falls in love with Hannah and stops going to the bar. After some time, Hannah takes him home to meet her parents, Cal and Emily. Cal is shocked to see she is dating Jacob and refuses to acknowledge their relationship, knowing full well Jacob's past as a boorish womanizer who treats women like objects. He eventually banishes both of them from the his house until they break up.
Finale
All the major players (except David Lindhagen - whose plot arc is never resolved) show up at Robbie's graduation where he is giving the graduation address. Jacob's speech is all about how he has given up on love. Cal can't bear to watch his son give up on love and interrupts him to make his own speech, where he acknowledges that he still does (and always has) loved Emily. He says he will never give up trying to win Emily back. This inspires Robbie to once again proclaim his love for Jessica, who this time appreciates his declaration. After the graduation, Cal blesses Jacob and Hannah's relationship and welcomes Jacob into his family. Robbie says he will wait a few years before pursuing Jessica again - she tells him she will look forward to it, kisses his cheek, and gives him one of the nude pictures she had taken to give to Cal. Emily and Cal stand next to each other as they watch their three children and Emily essentially says she no longer regrets their relationship. They smile at each other as the credits roll - unclear if Cal will ever win her back.