This isn't exactly what you're asking about, but a while back I heard a Dr. Sue podcast about extreme lifestyle cuckholding. It was weirdly disturbing. I was kind of upset for a while after I heard it.

She spoke with two guys. Each of them had gotten into a situation in which a bull had come into their lives and marriages, and sort of taken over. It seemed like the bulls were more interested in dominating and humiliating the men than in sleeping with the wives.

As I said above, it was upsetting to me, more so than just about anything else I had ever heard or read about people in the scene.

I'm deep enough into femdom that I've never really been into regular sex, and one of the things I had sometimes thought was that it might be possible to have a relationship with a woman who would go to someone else for sex. That was sort of the genesis of my interest in the kink.

I think that what it came down to for me, is that I have strong masochistic desires, but that the truth of what it means is sort of obscured by my positive feelings about and desire for women. What I mean is that wanting to be debased or used doesn't seem that bad in the context of a femdom scene or relationship. But in those cuckhold relationships, that mask was stripped away -- it was just this horrible stuff that was happening to those guys, who were stuck in it for odd psychological reasons.

It made me start thinking about my own desires for humiliation in different ways -- I tried to think about what it would look like if it was stripped of the fantasy element, or the beauty and appeal of a woman, etc.

All of which is a long way to go in order to say that I couldn't do it, and that it would be among my hardest limits.