I'm not into the idea of any of the humiliation side of things, but I have a lot of hot wife/ cuckold type thoughts.
I'm not sure that I'd like to watch my wife having full sex with another guy, but I love the idea of watching her wank off another guy. Or another guy wanking off over her tits while we're fucking.
I also like the idea that we agree before hand that her wanking him off is our limit but in the heat of the moment she gets carried away and sucks him off.
I would love to see her with 2 lots of cum on her. Either me and the other guy Cumming on her at the same time or me watching her wanking him over her tits first, then us fucking afterwards and me Cumming over her body.
Also love the idea of her being total centre of attention and getting off on having the attention of 2 guys.
I don't think she'd ever go for it, so it will probably only remain a fantasy, but I did mention it during a tipsy sex session once, and she didn't tell me to shut up! Also she sometimes sucks my fingers while we're fucking which massively turns me on, when I told her I liked the idea that it's another cock she's sucking on she said "what do you think I'm thinking when I do it?!"