At least the funnyman didn't actually grab the mic, but he did lip sync and bust a move as 50 Cent sang "It's Your Birthday" to Jim Carrey on his 47th birthday at the VitaminWater party in Sundance!

X17 caught a quick glimpse of 50 when he left LA for the big winter party Sundance Film Festival...we couldn't quite make out what he was saying, but dayum, he looks good!