Britney Spears surprised husband Kevin Federline with a Cher impersonator for his birthday. KFed was stunned when the Cher impersonator stepped onstage and performed his act. A fellow party goer said, "It was a special birthday indeed. Everyone found Britney's surprise really hilarious. Kevin and Britney and their friends were in fits. Kevin finished the night off by dancing to his wife's I'm a Slave 4U and then hitting the DJ booth to play songs from his new album."