A mark left on someone's flesh resulting from being slapped by a penis. The impact of thebulbous glans penis and narrower shaft leaves a mark with a shape much like that of the fruiting body of a mushroom.
Your mother wasn't very careful with her teeth when she was sucking my wang, so I pulled my dong out of her mouth and beat her on the face with it, leaving several mushroom-shaped welts that developed into bruises that were clearly visible when she picked you up from school later that day.
by Baller-Ass Nigga June 17, 2004
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