Another guy to turn into a play thing? I'm loosely thinking either your guy is out of his element and thinks he's hot shit (a gay playboy type character) who is the type to 'show men the door' the next morning, never calls, etc. Wealthy, and such--and gets his life turned upside down when he meets someone who not only dominates him, but turns his world (and sex life) upside down. Short term or long term. Bonus points for those open to tit-for-tat witty responses, heavy physical or verbal flirting, and kink.
EDIT: Also looking for a dark, jealous like sugar daddy (bottom, ideally but a switch would work too) for a line.