If you're easy on non consenting people being involved in other people's sexual experiences and fetishes - which is abusing them - where are you going to put the line?
How do you say it's ok for that guy to get his kicks undressing and playing with tampons in a women's changing room, even though it revolts, annoys and scares some of those women (which often adds to the sexual thrill of someone doing this kind of thing, their distress is arousing) and means that some women can no longer have any changing room, cos poor guy, it's apparently his sexual orientation to be a sex pest to women rather than awful behaviour choices being indulged - but say it's not ok for another guy to get his kicks stripping off and wagging his bits in a children's soft play area? If that's his orientation?
What about the guy whose orientation is rapist? Or serial killer orientation?
It's like the once you've agreed someone can legally be the sex they want rather than the sex they are you've opened the door wide to a guy of 50 legally forcing admittance to your kid's nursery. Because if you can choose one reality and enforce it, there's a powerful precedent to all other realities too. The door is open, the precedent is there. And the guy's really sad!
You may think it's extreme and silly, and a rational person has lines and boundaries. Yes, we've all fallen for that one; it's a good faith belief being used against you. Go and see how the salami tactics and the thin end of the wedge has been used in the past eight years to smash women's rights and child safeguarding. Is being used right now.
It is not ok to use other people sexually. Breaking other people's consent boundaries is not ok. There are no grey areas on this. And females are not born with a biological duty of needing to make male people's dicks happy. They are really not.