While the title might imply a Nevada-set romantic comedy, What Happens in Vegas doesn't actually stay in Vegas. After a debaucherous night in Sin City, two New Yorkers who've just met rigid, recently dumped Joy (Cameron Diaz) and relaxed, recently fired Jack (Ashton Kutcher) wake up not only hungover but also married. They're eager to get away from each other, but then Jack uses Joy's quarter on a slot machine and wins $3 million. They both want the money. And a divorce. ''We come back to New York, and the judge decides not to give us the annulment,'' Diaz says. ''He freezes the money, and we have to prove to him that we've tried to work on our marriage for six months.'' This includes living together (cue the toilet-seat jokes) and regular marriage counseling from wait for it Queen Latifah. And it leads to a battle royal, as each spouse tries to get the other to drop out of the marriage. ''It's very physical,'' Diaz says. ''We beat the s--- out of each other, but it's so much fun.''
Less fun was filming on location. ''In New York, the paparazzi were all over us the minute we put Ashton and Cameron on a sidewalk,'' says director Tom Vaughan (Starter for 10). ''In Vegas, you finish shooting and the last thing people feel like doing is going straight to bed. People would go out and then really pay for it: You've got to get up again and go to work.'' Through it all, Diaz and Kutcher managed to make the chemistry work. ''They both had that competitive edge, like sports people being put together,'' Vaughan says. ''They play off each other really well.'' That sounds like a formula for happiness and hopefully a hit. (May 9)