I am writing about a main character who begins the story as a virgin, and over the course of the story escalates her sexual behavior from 1 on 1 heterosexual sex to prostitution and then to what might be described as some more extreme, potentially risky sexual practises.
However, I am wondering how far is too far? How far can the story go before turning the titillating into a turn-off?
For example, the MC, as a prostitute with some magical abilities, has the opportunity to help a client with some taboo fantasies (sexualised cannibalism in this case) experience his fantasies without anyone actually being hurt, in a manner similar to a hyper-real VR that affects all the senses. As to why she might help such a person with such a fantasy, it's because doing so is (for her) no more difficult than helping any other client, and her goal is not to facilitate a present or future criminal act but to safely defuse it by making the (fake) reality not live up to the client's fantasy.
However, while this follows the MC's trend of ever more extreme sexual practises, would this (and other taboo fantasies that other potential clients might have) be a step too far?
By "A step too far", I mean that the content that may be titillating to some - mostly those with the fetish described - would be a turn-off to a large number of potential readers.
Describing sex in a non-erotic fiction is not a duplicate of this question... my work would be considered erotic fiction, and there are most certainly no 'fade to black' moments.