Any asshole you don't want fucking your female relatives, e.g. your mother, sister, aunt, niece, cousin, grandma, pets, steps, brother, nephew, uncle, grandpa, best friend, any friend, possibly your enemy, the gas station attendant, the milkman, your doctor, the barber, the bar tender, your investment banker, the ATM outside your bank, the ATM inside the Walmart. the AI inside the Target, the local cops... oh, wait, the cops don't belong on this list.
My cousin Honey Boo Boo told me that her dad first boinked her mom then came after her. "What a mother fucker!" she said, as she came at him with a baseball bat. I love my cousin Honey Boo Boo.
Somebody you don't want fucking any of your female relatives, including your mother, sister, aunt, niece, steps, brother, cousin, nephew, friend, pets, uncle, etc, etc., etc.
My father is a real mother fucker. After fucking my mother, which was bad enough, he wanted to fuck me. Gross!
Mother fuckers like your father. Think about it, he fucked your mom, right? That is how you are alive on this planet. Your father was indeed a mother fucker.
Son: Dad, you mother fucker.
Dad: I know, I fucked your mom.
Guy 1: You are a mother fucker!
Guy 2: Your mother says so too!
Anything that goes on for too long
1. That mother fucker still owes me money.
2. This party is boring as a mother fucker.