While partying in Utah for the Sundance Film Festival, Jim Carrey got a very special birthday serenade from 50 Cent. The rapper invited the actor up on stage for a rendition of ’50s hit It’s Your Birthday, during which Carrey, whose 47th birthday was Saturday, reportedly showed off some impressive dancing skills. “Jim was lip-synching and bumping and grinding,” a source told the New York Daily News. “It was pandemonium in the best way.” Chris Rock also joined the rapper onstage at one point.