Like a fuck buddy except this person isn't your buddy in any way shape or form. You have nothing but contempt, loathing and disgust for each other as people. Yet you call them or receive a text from them every time you're lonely or they're horny and you get it on. There will be no talking, except to trade insults. You will have no need to discuss "keeping this a secret" as you're both too ashamed to reveal this to anyone.

Ex's, long term partners and co workers can all become Fuck Nemeses.

A casual invitation / threat used by an individual that is not afraid of fucking someone up.