Definitions by ASHLE HARPER

muff muffin 

A term derived from the latin word, "muffcake", but translated to english.
Short for your-stupid-and-you-think-you-know
-everything-but-
you-just-suck-at-life-and-need-to-die.

Can also be used in place of eff.(see examples)

"Andrew is the biggest muff muffin of life...fosh!"
or
"What the muff muffin are you doing?"

muff muffin by ASHLE HARPER December 1, 2006