The act of "tucking" in ones penis and balls between his legs, to simulate the image of a vagina. The character "Buffalo Bill" does this in the movie Silence of the Lambs and dances to Q Lazarus's Goodbye horses. The typical "mangina" can be found in scenes also from such movies as, The Clerks and Scary Movie 2.
A word used for a gay man's pooper. Gay mendon't have vaginas for a penis to be inserted into. As such, they deam their butt plugging poopers to be there "mangina".
Kevin screamed and moaned as his mangina got pounded by his well hung boyfriend!