Russian word is the mix of the "Govno" (what equals to english "shit") and "mes" (from "mesits" and means "mix"), and common
straight sense - the person who knid/mix the shit.
In russian
straight-men language "person who knid the shit" is the non-traditional sexual orientation man of active position , because he "knid the shit in the asshole of his partner by his dick", and
even passive homosexual man because "he like to knid his shit, which is kept in his asshole by the his f*cker's dick".
The figurative sense is abusive word to guy, because in
Russia all that connected with homosexuality is the little abusive, not seriosly, with laughing and also abusive word in friendly chating