There was a discussion a while back about /d/ themed cursed items, which led to discussions of ERP in the settings of actual GMed rpgs. I've been looking but haven't been able to find places to get in on something like that. Suggestions?
You could try the Book of Erotic Fantasy and just build upon that.
I remember there being a much more specific book, that even had in it a setting and plane/world, but I cannot for the life of me remember its name.
There's Encyclopedia Arcane - Nymphology
It's a third party splat book for tabletop roleplaying games. I've never read it specifically, but I've read others in the series and they seemed pretty good.
Here's a link to the pdf.
/d/ themed items, races, and spells have been fairly prevalent throughout all the D&D editions even without fa/tg/uy or /d/eviant input. You can't go one campaign book without some sort of transformation, and there's almost a requirement for every Monstrous Manual to have at least one scaled race that can transform people into either more of them or another scaled race.
Outside TF there's excessive body odor / fluids, doting inanimate objects, tentacles literally coming out of the woodwork in some campaign / spell books, petrification…
Fun stuff for all.