The smell that exists when a bunch of teenage boys sleep and eat in the same room for over 24 hours without showering. If you experience the ass muffin smell you are advised to internally combust, because your life is over.
zomg that hax! He UnleasHED a nasty ass muffin smell!
by Greg J.B March 21, 2007
The act of stuffing one or many muffins down your pants, while promptly sitting down on the doughy mass. Upon sitting, you take the muffin mass, ball it up and eat it.
dude, you really need to get a taste of Chris's ass muffin, it's to die for!
by theprettiestbaglady October 27, 2008