Fonzie, or too Fonzie.
Fonzie is when you
jam your
thumb into another persons anus, one of the
two parties involved in the act yell Heeeeeyyyyyyy!
Dude 1- So I was banging this
chick, and I
stuck my thumb in her
ass, and she yelled Heeeeeyyyyy, so I pulled it out.
Dude 2- Oh so you fonzied her!