The act of splitting an oreo cookie in half, wiping the cream part on one's rectum, and having another party proceed to lick the cream off.

The definition of this word evolved from other words involving pastries with sexual relations, specifically rimjobs.
Dude last night was so awesome because after I bought a brand new bag of oreos Jessica gave me an oreo dirtpie.
by Streetgang September 24, 2009
Get the Oreo Dirtpie mug.