N. the disgusting, bottom part of the muffin that, it would seem, was ignored in the delegation of yummymuffin ingredients like chocolate chips, blueberries, and nuts. They are most commonly discarded or left to rot on a lunch tray.
Stina Shall: Namie, why haven't you finished your muffin?
Lyme Ninja: Pft. I never eat the Muffinbutts.
A phrase describing any female-female sexual position where the vulva of each female are bumped and rubbed against the other. May also be used to describe lesbian sex, even though not all lesbian sex entails vulva-to-vulva stimulation; similar to "knocking boots" being used to describe sex in general.