This is when a dude is sitting relaxed on the ground, and a girl leans her legs on his shoulders; facing away from him, so her ass is pointed towards his face, and she uses her legs to drag and pound his face inn her ass, to the beat of the music. Pretty painful, but really worth it.
"Dude, what happened to your face?" "I got a brokenose twerk yesterday" "Ahh, ok, but good pain right?" "Good pain"