Green’s Dictionary of Slang

1. an act of intercourse in which one or both of the partners feels no affection towards the other.

1968		Realist 84-93 8: ‘With him, every fuck is a Grudge Fuck! Courtship is unheard of in his world. You see, you grab, you do!’.
2006		G. Iles Turning Angel 145: Intercourse with the victim was an act of vengeance if not outright rape. A ‘grudge-fuck,’ I believe it’s called.
2011		C. Brookmyre Tale Etched in Blood & Hard Black Pencil [ebook] Last night, though: that was a grudge fuck, thirty years in the making. How was it possible to have such a good time with someone you hated so much?
2012		E. Daniels On the Rocks 151: I want this to be a grudge fuck. That’s how I want to remember it, just sex and nothing more.

2. (US) an act of intercourse undertaken simply as a result of a grudge, usu. against an absent partner.

1984		E.G. Denholtz Having It Both Ways 45: ‘I picked out his best friend to seduce. Let me tell you something. It's true: Revenge tastes very sweet.’ ‘Call it a 'grudge fuck. I don’t care’.
1994		S. Isaacs Shining Through 567: ‘Bonnie, baby, I was PO’d at Lindsay and felt like a grudge fuck, and you were available. It didn’t mean anything’.
2004		C. Hiaasen Skinny Dip 172: I’m afraid it was a grudge fuck [...] I jumped your bones just because I was furious at Chaz.