The act of rubbing your dirty bare ass on almost anything. Likely targets are, your college room mate's sheets or pillow, an ex-girlfriend's or ex-wife's hair brush, someone else's body (you have to do this one quickly).
Your ass could dirty from a good sweaty workout or a particularly nasty shit. Either one works.
After playing 2 hours of basket ball the guys were sitting around watching TV. Before he knew what happened I dropped my drawers and slid my bare ass down his whole thigh.
That was a nasty cooney dog.