To fuck someone without them even knowing
"Yo Ted got sucker fucked the other night, he had no idea.."
"That guy never lets anybody know when hes going to fuck them, what a sucker fucker"
Fucking someone unexpectedly or out of the blue. Much like sucker punch, but instead of punching them you are fucking them.
THIS IS NOT RAPE!!!
Sucker Fucking is wanted, just unexpected, like a surprise :)
I went over and Sucker Fucked Vikki while she was asleep.