A type of homosexual intercourse whereby a man inserts his penis into another penis and climaxes inside. Similar to the way snuffleupagus might reproduce in nature. The seemingly impossible biological properties of this act make it all the more pleasurable when actually completed.
Ohhh woha! David just tricked me into watching a video called kids in the sandbox, it looked like a regular adult film until this lady started mushroom stuffing the man with a dildo. I need to go rinse my eyes with drain-o!