N/tr.v Mix of fuck and shit. Put together, it means to shit on someone in a vigorous, quick, and lively way with sexual intents (usually forced) and is considered sexual harassement.
An exclamation combining the words Fuck and Shit, it can be used as a negative statement standing in for "fuck that shit", or in a positive sense "that's the fucking shit".
Typically this portmanteau of fucking shit is used to swear in the presence of those who would otherwise frown upon the use of profane utterances: teachers, parents, and obnoxious religious acquaintances.