Can also be used in other forms such as "motherfuckerer" (a spin on the term motherfucker, "sister fuckerer", etc.
You can also add "er" several times to show that you don't intend to be offensive. i.e. fuckererererer...
Fuck you, you motherfuckerer, you.
Oh yeah? Well fuck you, you fuckerererererer... wait, what was I talking about again?