Fraternity pale from Yale, 1919.
Fraternities and sororities are definitely the closest precursor to BDSM clubs (both the real kind and the fantasy). Hazing of pledges has often included D/s, spankings, public humiliation, nakedness, bondage, and even tatoos or brandings. And it’s been going on for over a century. And despite opposition from school administrations, it’s all seen as perfectly vanilla, even non-sexual, by the wider culture. You can strip the pledge boys naked and put them on leashes and pain their cocks blue before paddling them silly. It isn’t about sex. Obviously. ’Cause that would be gay.