So let me see if I am getting this straight, you want to find couples where you and your boyfriend both get to play with some guys wife while you make him sit in the corner and keep to himself?
Yeah right! Are you serious?
Actually if you proposed this idea to a thousand different couples you probably would find a few that would go for it. There are some guys that are so big into the voyeur thing or are so desparate to see their wife with another woman they may go for it.
There are probably a lot of couples that would agree to where just the girls play but the guys are restricted to playing with only their own partner. But making some guy just sit in the corner while you titty rub on her while your boyfriend throws her legs up over his shoulders and lays the lumber to her is really asking a lot.
If you ask a lot of people a few would probably do it but you will get a hundred "FUCK YOU!"s for every acceptance you get.