Ashton Kutcher says if his new romantic comedy A Lot Like Love tops the weekend box office, he'll drop trou. "If we are the No. 1 movie in America, I will do a Calvin Klein underwear campaign," he told Access Hollywood. "It's actually a bet that I made with my producing partner, so we will see what happens." And what if the Nicole Kidman-Sean Penn thriller The Interpreter takes the top spot instead? Says Kutcher: "Oh, crap I thought that was opening next weekend."