R. Kelly laid down a mind-blowing live performance ... for a dude in a Las Vegas sauna, and the video is freakin' amazing!
R. was kicking it in the sauna at a 24 Hour Fitness in Vegas last weekend. When he first walked in, naturally ... someone asked, "Are you R. Kelly?"
Kelly -- who, oddly, was fully clothed in the sauna -- didn't admit it was him, but instead said he could sing like R. Kelly. Then he just started belting out "Bump N' Grind." Best (non-porn) sauna video ever!!!