Sack Drum
When a male is bored in the shower and stretches his scrotum out and bounces his penis off of it so that looks like his penis is bouncing on a trampoline.
Guy 1. "You know when you're bored in the shower and you stretch your ballsack out and bounce your dick off of it like it's bouncing on a trampoline?"
Guy 2. "What the fuck??? No...."
Guy 3. "Oh, you mean playing the sack drum?"
Guy 1. "Yeah, exactly."
Guy 2. "What the fuck??? No...."
Guy 3. "Oh, you mean playing the sack drum?"
Guy 1. "Yeah, exactly."