Hoop slap is like a happy slap, except you do it with your anus. The hoop slapper must first relax their anus muscles just enough to be able to slap their friend round the face with it when they're least expecting it, resulting in them being repulsed and humiliated, yet left breathless from the shock and rolling around the floor with laughter because they didn't see it coming!
Hoop Slapper: *approaches from behind* Hey gurl...
Victim: Hey you, whats up! *turns around*
Hoop Slapper: *hoop slap* Gotcha!
Victim: *gets hoop slapped* Oh what the hell! Hahahaha. I'll get you next time!