I have an unusual fetish and I feel deeply ashamed

Disclaimer: For the sake of keeping this sfw and not derailing the conversation completely, I will not go into specifics. It is legal and only involves consenting adults, but a majority of people would consider it disgusting.

Here is my situation. I have had this fetish for as long as I can remember. When I first started discovering my sexuality, I would fantasise about it. There is no traumatic event or logical explanation why I have this fetish, I just do. I also wasn’t exposed to porn especially early.

The thing is. I know that the people in my life would view me differently if they ever found out. I wish I could stop fantasising about it, but it is a part of me that I can’t get rid of. It makes me feel ashamed and abnormal, and the only viable option in my mind is to take it to my grave and never tell anyone. The possibility of finding a partner with this kink seems unlikely at best. I can get off on the idea of regular sex, but my ultimate sexual fantasy is something that I will probably never experience, and makes me feel sick and perverted every time I think about it.

I have been dreading making this post for the fear of being ridiculed, but I feel like it’s the only way to get this weight off me.

Edit: Since I am already making this post on a throwaway account and confessing I might as well tell you. Otherwise you are just going to speculate wildly. Here it goes, something I have never told anyone: I want to get pissed on.