The act of a man slapping another person in the face with the head of his penis (a.k.a. mushroom stamping) after giving them a good messy ass fucking, leaving a smear in the shape of a mushroom, or in this case, a Goomba. The origination of this definition comes from the mythical creature dwelling in the Mushroom Kingdom of Super Mario Brothers games. In the original game for NES, the Goomba sprite was identical to the mushroom sprite, only it was brown and had eyes.
by Mattlick July 03, 2008