This topic came up not long ago between myself and some bi friends of mine that swing. This is a m/f couple btw. They are both very nice,attractive people around mine and hubby's age. It started out as a "what if" type thing because he and I flirt all the time and talk about sex and shit like that.
We were talking about how they set their rules and who they play with ect.
Anyway, two of their rules is that they always play together.No pussy sex for either partner. They only have pussy sex with each other. ALWAYS. NO EXCEPTIONS.
So I'm thinking. "WTF? What's that leave for your other partners?" And I tell him so. I was like, "Well doesn't really seem fair to your third wheel if that's something they need from the encounter."
And he goes on with this big spiel about how he loves his wife and that's something only they share...blah, blah, blah...
I told him that would be a deal breaker for me and he was astounded. Like I was the freak for needing something like that. That maybe I wouldn't pick him and his wife for a party. He tried to tell me that he and his wife always make sure their partners walk away happy.
I told him THEY might walk away happy. But for someone like me, if I'm gonna have sex with another couple and don't get what I want from the scene, I might walk away midly amused but I would also feel a little used and dejected.
I respect the rule. I get that it's something they only share together. Understandable. But they're not willing to see that it's a deal breaker for me. That maybe I'm just not their girl. It was strange. Like he was really let down by me saying that or something.
I don't know if they were about to invite me to be with them or just dipping their toes in the waters.

Wierd fucking conversation though.
And just for the record, she is pretty but he's the one I'm more attracted to. If I have to fuck her then I'd damn well better be able to fuck him too.