I didn't want to post anything before you responded Niara as to not dogpile and also in case my information was outdated, but that also struck me as the opposite of what Loviatar is about -- Loviatar in many ways represents the opposite of what I'd think of as a healthy bdsm practice would be. A Loviataran is the kind of person who'd care about your limits and don'ts only so they can abuse them to hurt you even more. Loviatarans don't want you do die because when you die the suffering stops. But I'd much more expect them to want to leave marks, scars, chronic damage and similar (including emotional scars because they are equally into mental anguish and suffering) just because they know every time you hurt it will bring back memories of the suffering.
BDSM as a mutual, sexual experience would be more in the alley of the Sharessans or even Ilmatarians. Ilmater's holy symbol is a couple of tied hands, for gods' sake -- compare that to Loviatar's scourge
