I probably need a better noun than thing but couldn't think of one. Being a bit kinky used to be the stuff of Carry On films and nudge nudge wink wink type conversations. It maybe meant the odd sex toy or the stuff in the film 9 1/2 weeks. Now it seems to be used to cover antisocial often criminal sexual behaviour like exhibitionism and seems to be used to try and normalise sexual predatory behaviour.
Is it a generation thing or just a subsection of men who use the term? Can't recall anyone in real life talking about their "kink" but social media seems full of it and it seems to sometimes include paedophilia.