Or two or more consulting adults in an S&M relationship.
S&M is consensual, there are safe words and guild lines by those who engage. It does not usually involve more than two people, the dom and submissive, and does not have to involve sex. Does not require any particular sexual orientation by those involved.
Think of it like willingly entering a boxing ring or getting a personal trainer.
Except getting a trainer or boxing is not an act of perversion.
I will say this. Many of the right on this board predicted the perverts would come out of the woodwork and start demanding that their nonsense be accepted as normal after this decision
You don't understand S&M, it is about trust not perversion. If you close your eyes and fall backwards you trust someone will catch you. S&M is not that different. There has to be absolute trust by the submissive for the dominant. It is about learning to let go, not to fear. Some jump from planes and off cliffs, some go deep free diving, others seek out S&M.
When you get in a boxing ring you trust the other person to follow set rules and not to just pound the life out of you to be abusive. A trainer is there yelling to motivate you and you trust them not to have you do something harmful in the process.
A mild pain to heighten the senses can be part of S&M, but it can be about submitting to verbal commands and no physical abuse or pain at all. Being hooded or gagged can open a whole range if new senses, much the same way a blind person sees the world through heightening of his other senses. It is not about walk out all bruised and beaten barely able to stand on your own legs or bleeding all over the floor.
Find an S&M site and do some learning.
The only 'perverts' are those with closed minds so tight that it suffocate any reasonable thoughts