Jack muffed up Jason's face after Jason attempted to finger Jacks mothers asshole while she was sleeping.
by scott January 30, 2004
muffed up means fucked up. use "muff" to replace fuck. very fun to use so you dont get in trouble by the parentals or offend the old folks. use different variations of muff too-muffer, muffing, etc.
by Kyle Ernesti June 16, 2006
by Alex Hildenbrand May 05, 2010
by iohnoprngs March 22, 2009
We was about to hit it right, but i reached in, felt that bush and though "damn, this bitch muffed up." She knew she muffed up too.
by Fisherella June 30, 2009