The act of calling someone a Motherfucker, but by switching the first letters of both words around (aka Spoonerism), that individual becomes stupified by what just happened and fails to reply with any sort of equally or greater comeback.

See Buck Futter and Sock Cucker.

A fothermucker has a serious design defect
Never play him for a sucker 'cause he earns respect
It's like a CD in your system that you can't eject
It's the hardstyle DJ that just wrecked your neck

A fothermucker has a serious design defect
Never play him for a sucker 'cause he earns respect
Like the best looking bitches keep your dick erect
I'm a wild fothermucker, motherfucker dig that!

for those afraid to say motherfucking, is the word "fothermucking"

The polite way of saying MOTHERFUCKING.

Sometimes we would like to swear our f*king heads off but can't.

VERB: FOTHERMUCKING
NOUN: FOTHERMUCKER

Motherfucker, said by someone who can't speak properly.

you are a fothermucker