What Happens in Vegas is a 2008 American romantic comedy film from 20th Century Fox starring Cameron Diaz and Ashton Kutcher. The title is based on the Las Vegas marketing catchphrase "What happens in Vegas, stays 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.