A Sherker
A Sherker is when you cram three fingers in someone's ass without even bending them, just three fingers, one after the other, like a finger parade in the butt!
He did a Sherker in the bathroom and it echoed all the way down the hall.
He did a Sherker in the middle of class and got a detention.
She did a Sherker in the hallway and laughed the whole way home.