[HUGE TRIGGER WARNING] Anyone else's SA's fantasize about 'sharing' them?

I feel like I've sat on my hands about this long enough but it's something I've experienced and a pattern I've noticed with others that I'm deeply curious about. Obviously, please only respond if you're in a place to do so because I know this can be really triggering.

Shortly before Dday, WH let it slip while we were being intimate that he fantasizes about 'sharing me.' Afterwards we had a conversation about it in more depth. I thought at first he might be into cuckholding stuff but it's like, cuckholding without the shaming of the person watching. Like, his fantasy is me going out and having sex with as many men as I want, whenever I want, and sending him photos or videos of it along with messages like 'wow, this guys great, thanks for taking care of dinner tonight, I think I'll be home late!' That or literally just having a party and watching various men have sex with me, either one after the other all at once. He explained it to me that it's not about me having sex with 'better' men (like Cuckholding) but more like him encouraging me to have a good time with as many men as I like because he 'gets off on watching me get off and enjoy myself.'

After dday I went through the full expanse of his messages (open phone and account policy) and out of his 54 APs (he was a prolific sexter,) there were two men he engaged with and their sexting was exclusively focused on the fantasy of 'sharing' me with them (complete with the AP giving them a hi-five after and saying 'thanks man, she's great! You're lucky!') Most of his acting out occurred over a two year period and as it escalated (rapidly,) it's easy to see through his browser history and sexting etc that more and more of the porn he consumed and the sexting he engaged in was focused on this fantasy.

I'm asking about it here because I've seen so many other partners of SAs (and just WHs in general) share that their WH also is really into this fantasy, and I find that extremely interesting. Like, I've seen it enough that I feel like there's more than coincidence at play here.

Why do you think this is? Do you think it's projection? I have a theory that part of my WH being into this was him projecting what he was doing behind my back on to me in his fantasies so he'd feel less guilty or less shame around his affairs. But then I've seen others speculate that this is their way of adding their wives into the porn-style situations they consume in order to feel better about it. I can see this making sense for some, but in my case, porn useage didn't factor in to what we consider to be his acting out behaviors (his were sexting and physical affairs) -- he actually consumed very little porn in the scheme of things.

Really just curious if anyone is open to this discussion. Again, please only respond if you're safe and comfortable to do so but I just find this so interesting.