grandmother fucker 

One who deliberately (or inadvertently sometimes) fucks their grandma. Note the difference between this and a "grand" mother fucker.

Joe: Steve, where were you last night?
Steve: Ahh .. umm.. I was out playing with the dog.
Joe: Don't lie, you incestuous grandmother fucker! I have it all on tape!
Steve: WTF?

grandmother fucker by african_dude March 25, 2008

grandmother fucker 

someone who, willfully or against his or her will, engages in sexual intercourse with someone who has grandchildren.

the person with grandchildren doesn't need to be the actual person's grandmother.

Rob: Dude, what happened at the bar last night?

Tim: didn't you see? I was talking to that old lady from the back there.

Rob: how old was she,

Tim: i don't know but when I got back to her house her grandchildren were running all over the place so I took her to the basement, put a sock in her mouth and fucked her. After about 10min her grand kids came down and started watching.

Rob: WTF you nasty ass grandmother fucker!

grandmother fucker by Rockman01 July 27, 2010

grand mother fucker 

1: The greatest mother fucker alive.

2: King/Queen of all mother fuckers.

You just got served you Grand Mother Fucker!

grand mother fucker by Vulcanus January 17, 2005

grand motherfucker 

When the regular motherfucker just doesn't cut it; a higher level of motherfucker.

It's going down now, you grand motherfucker!

grand motherfucker by The Great Dark February 8, 2015

Grand motherfucker 

A respected older motherfucker who has been promoted by excelling as a motherfucker or by fucking one or more grandmothers

John is now a Grand motherfucker.

Grand motherfucker by JAKINTEXES July 10, 2011

grandmotherfucker 

One who fucks a grandmother

Steve Stifler in American Wedding is a grandmotherfucker, since he fucks Jim's grandmother.

grandmotherfucker by Greg Pugh August 14, 2003

Grandmotherfucker 

Also known as your grandfather.
Named for mating with his wife to produce children who then become parents of his grandchildren.

Ben: Me and my motherfucker just went to see my grandmotherfucker for Motherfucker's Day (also known as Father's Day).
Gregory: My motherfucker (or my father) is such a charm and treats you with love.

Grandmotherfucker by gregben July 6, 2021