Honestly? Bookshops that look sketchy on the outside tend to have the wildest stories tucked behind the counter, but that's getting harder to find. I've gone deep on a few indie author newsletters lately, the kind that don't even advertise on the big platforms. You have to follow a chain of reblogs or recommendations from other readers in niche forums. Found this one writer who does erotic sci-fi centered on alien cultures with completely different concepts of intimacy and power—nothing human about it, which was a breath of fresh air. The plot actually mattered, the spice was a consequence of the worldbuilding, not the only point.
A lot of people swear by the serial apps, but the algorithm there feeds you more of what you already like, which kills the 'unique' part after a while. I had to deliberately seek out tags I usually avoid, like 'monster romance' or 'historical mystery-erotica blend,' and that's where I stumbled onto some gems. There's a web serial called 'The Gilded Cage' that's a slow-burn political intrigue in a fantasy setting where the erotic tension is all about forbidden magical bonds and oath-breaking. It's not marketed as erotica upfront, which might be why the storyline is so solid.
My biggest tip is to look for cross-genre mashups from small presses. The stuff that doesn't fit neatly into a category often ends up with the most inventive plots. I picked up a noir-pulp romance from a micropress last year that was all about a detective and a femme fatale using seduction as a weapon in a magic-realist 1940s LA, and the writing was sharper than most mainstream thrillers. You just have to be willing to sift through a lot of self-published dross to find those, but the hunt is part of the fun for me.