To boldly go where no man has gone before
AI generated erotica is likely to be indistinguishable from the human generated or so ludicrous as to be comedic and ridiculous.
Straight up porn is typically incredibly unimaginative and repetitive. A twenty clause Prolog program could enumerate all the possible scripts without enlisting the heavy guns of AI/LLM.
Mining existing modern erotica probably not worth the candle - classics like The Scented Garden might be more fruitful.
If you had access to accurate, detailed data on how real people interact from initial contact through to forming a romantic and/or physical relationship you might be able to construct an effective model but I suspect it might be closer to Jane Austen (or at least Barbara Cartland) than the formulaic rutting typically found on Porntube.
I would imagine most of humanity would find Antonio Conova's Psyche Revived by Cupid's Kiss more erotic, without being pornographic, than most of the internet's offerings.
Without romance and fantasy the erotic is like raw fava beans without (coarse) salt*.
Inevitably someone is going to combine the life-like sex doll (a là yourdoll.com) with mechatronics and generative AI to create a Barbie-stein doll but given the typical human male's acknowledged limited stamina in this arena I suspect the Ken-stein doll might spend less time deactivated in the closet. :)
I don't even want to think about the leather and whips side of this let a love adding de Sade to this depraved brew. :)
* try it. I think I found this antipasto in Elizabeth David's Italian Food