exploding mushroom

An action involving one person joining the tips of all of their fingers together, coming up behind an unsuspecting person, and shoving their fingers up their butt while opening the hand and making an ecploding noise.

I'm going to give you an exploding mushroom if you don't cut it out!

exploding mushroom by Brackettmaster April 23, 2006

exploding mushroom stamp 

While in the act of doing a mushroom stamp, you jizz(explode) at the same time.

Do the exploding mushroom stamp to your mother

exploding mushroom stamp by kuter punch February 27, 2009