I only did it by mistake. He is one of these guys with large hanging black shiny balls and he was lying in bed with his legs hanging at the edge. I started licking his balls and I licked his asshole right underneath. He is a clean guy and it wasn't repulsive. He moaned and approved. the position was uncomfortable - you can imagine balls and cock on my face, and we stopped and changed the game. But i can understand when you see those perfect hairless male dark brown buttocks, they're so pretty. Maybe I would try again