What Happens in Vegas
In New York City, high-strung equity trader Joy Ellis McNally (Cameron Diaz) is dumped by her fiancé at a surprise birthday party she throws for him. At the same time, easy-going carpenter Jack Fuller (Ashton Kutcher) is fired from his job by his father, Jack, Sr. (Treat Williams). Both become emotionally distraught and, with best friends Toni "Tipper" (Lake Bell), a bartender, and Jeff "Hater" (Rob Corddry), a lawyer, take a debauched trip to Las Vegas.
Joy and Jack meet by chance when they are given the same hotel room because of a computer error. After clearing up the misunderstanding and receiving upgraded rooms and coupons to various clubs, they party and drink together and end up getting married. The next morning, they realize it was a mistake and decide to divorce.
Before they do so, Jack uses a quarter Joy gives him in a slot machine. He hits a three million dollar jackpot and Joy reminds Jack that they are married and hence, she is entitled to half of the money. The couple return to New York, where they attempt to divorce. The judge (Dennis Miller) declares that the couple cannot divorce until they attempt to co-exist for six months, while attending weekly sessions with a marriage counselor (Queen Latifah). If they work at the marriage but still want to divorce after six months, each will be permitted to keep half the winnings. If either party does not cooperate, the money will be tied up in litigation by the judge.
The newlyweds devise more and more cunning schemes to undermine each other, such as Jack telling Joy that their counseling session is canceled to prove she's not committed, and Joy inviting girls to their apartment to try to get Jack to cheat on her, throwing a party where Jack's friend Dave shows up. Jack gives Joy's ex-fiancé, Mason (Jason Sudeikis), her engagement ring back without Joy knowing. At Joy's job retreat, Jack and Joy find themselves developing an unexpected attraction to one another, and they soon realize that being with each other has brought out the best in both of them.
After they get back from the retreat, it's time for the judge to decide what happens to the money. On her way to the hearing, Joy sees her ex-fiancé Mason, and he tells her that he wants her back. He gives her back the engagement ring and tells her that she is good enough for him. Joy realizes that Jack set her up to get back with him, therefore cheating on him and letting Jack keep the money. Joy walks away from Mason and goes to the hearing. At the hearing, their marriage counselor testifies that the couple truly tried to work on their marriage. The judge decides that they will split the remaining 1.4 million dollars (after taxes, bills Joy ran up, and money Jack spent on his new woodworking business). Joy tells the judge she doesn't want any money and gives the engagement ring to Jack, telling him she officially doesn't want anything from him. Jack realizes she knows that he talked to Mason.
Joy gets the promotion she'd been working for, but tells her boss she would rather be happy doing nothing than doing something she hates and being miserable. Jack talks to his parents and they tell him it looks like he and Joy are in love. Realizing his mistake, he goes to find her. Tipper tells Jack that she quit her job and that nobody knows where she is. He has a suspicion that she has gone to a beach (Fire Island, New York) that she told him about, the only place that makes her feel truly happy. Jack asks her to be his wife (again) and she says yes. As the two embrace, Joy says that she quit her job and has no idea what she's going to do. Jack reminds her that they have a lot of money between them. Joy states that they hit the jackpot, to which Jack replies that he certainly did (referring to both the money and to Joy).
=== Epilogue ===
During the credits, we see Tipper and Hater on the day Jack and Joy get married. Tipper and Hater subsequently enact a plan of revenge on Mason, devised by Tipper earlier in the film. Tipper and Hater ring Mason's doorbell, and when he answers, Tipper slugs him in his testicles. He moans in agony and drops to his knees asking "Why?", and she responds emphatically "You know why!", and Tipper leaves with Hater.
Post-credits, Dave is telling Hater about a party that evening, but Hater no longer wants to associate with Dave, citing Jack as being "the glue" that held the two of them together as friends. With that, Hater simply leaves. Dave asks a random guy on the street if he likes to party.
comedy, cute, entertaining, romantic