Are Paris Hilton and Ke$ha at war?

"Tik Tok" singer Ke$ha, 22, has a No. 1 single, but she wasn't always living the good life. She first met Paris when the heiress dropped by Ke$ha's Nashville, Tenn., home to film an episode of The Simple Life. But years later -- after she hit the recording studio -- Ke$ha paid a visit to Paris' home during a party and left quite a surprise behind. "We were all dancing," says Ke$ha. "I got overexcited and ralphed in her closet." But Paris tells Life & Style she had no clue! "I had no idea she threw up in my closet, and if you're reading this, Ke$ha, I'm not mad," insists Paris. "You just had a little too much fun. It's all good. The only person who's probably mad is the housekeeper who found it."