If a couple had a child and attempt to have another or just plain having sex, then the man is a motherfucker due to the fact that the man's spouse became a mother after having a child. Hence making the man(father) a motherfucker.
Your father is a motherfucker.
by The Professor March 31, 2003
Get the motherfuckermug. Someone who fucks their family members and doesn't even bother to clean up after the mess, what a mother fucker!
Fat Hillbilly fucking his mom, didn't even bother using a condum, and now his bed is full of cum - what a dumb mother fucker!
by Anthony P. August 17, 2003
Get the Motherfuckermug. 
We all up in this motherfucker.
by Half Ounce of Kush January 30, 2008
Get the motherfuckermug. (Variants; Mammy, Momma, or Mommy may replace mother. Eater, Grabber, Jumper, Kisser, Lover, Rammer, or Trucker may replace Fucker.)
A despicable person.
A despicable person.
by Light Joker June 7, 2004
Get the Motherfuckermug. 1. One who fucks mothers
2. A mother who fucks
3. The mother of those who fuck
Used as an insult to others.
2. A mother who fucks
3. The mother of those who fuck
Used as an insult to others.
by jetdog9 October 27, 2003
Get the motherfuckermug. by motherfuckingmotherfucker May 29, 2003
Get the Motherfuckermug.