That’s part of why I said communication is important. Let it evolve. For example, the couple I mentioned he didn’t want to be humiliated. He was not allowed to touch her without my permission. And he enjoyed preparing her. I would text him your marriage bed in 20 minutes. When I walked in she would be spread, wet and ready. A lot of it for them was the taboo that I fucked his wife whenever I wanted to. That any time she had cum in her it wasn’t her husbands, he wasn’t allowed to. We enjoyed when we would be around other people that only the three of us knew her wet panties were because I had just fucked her.
It all depends on what the three of you are comfortable with. Some like the open humiliation. Some it’s somewhere in between. Some like my first couple it is the act of that I wanted to own her body, the husband lost his rights to his wife sexually, and that whether he was there or not when I wanted pussy I was going to use hers. He needed my permission to touch his wife. Plus as your couple’s contract states, when I said spread your legs she had to open up no matter when or where.
it seems to me from the little you’ve said he is submissive to her and their start down this road is as a cuck he accepts that another man owns his wife’s body. Plus as a husband what goes through his mind? Preparing his wife to go out with another man. Watching them together. Knowing that other man is going to decide his sex life including when, where and who is going to fuck his wife.