So OK. Some fetishes really only work as porn. For example, there's a fetish around drunken women. Not the stuff where the woman is supposedly passed out and some guy rapes her. I don't mean that at all. The drunk woman fetish is not at all about rape. It's about the drunk woman as erotically stimulating in her own right. Simply watching a woman get drunk and keep on drinking is arousing for someone with this fetish. Sex doesn't need to be included. At most, the woman might gradually remove her clothes. She doesn't even need to masturbate. And no, the woman doesn't really have to be drinking alcohol, so long as she's a good enough actress to be able to fake it.
Do you see how this really only works as porn? Few girlfriends would be willing to just sit there and drink themselves into oblivion - and the ones who are willing should probably not do it, as they're probably alcoholics. Meanwhile any prostitute who would put herself in such a vulnerable position as to get blind drunk with a stranger is insane or moronic. And neither girlfriends nor prostitutes are likely to be good enough actresses to be able to fake it. The only practical and safe venue is porn.
Can you think of any other fetishes that really only work as porn?