I see this whole thing as a very specific and somewhat tragic occurance. This doesn't fit our definition of "poly" either. Its not even remotely a "poly quad". It is two old flames using swinging as a gateway to traveling a path they had thought lost forever.
Mrs 2TT is exploring an unrequited love. The first post acknowledges that Mr P was a love that pre-dates her marriage that circumstance never allowed because at that time she was following vanilla rules.
We *completely* agree with bbarnsworth. Mrs Mix and I, now that we understand the terms, actually venture down the poly path. We both get emotionally involved with play partners, play separately, and even explore long term *secondary* relationships.
We do not have "old loves" from *before* we knew each other that we pine for. If we did, we would *not* turn those sexual. You guys now have and yes, it was not a good idea. The only way to fix that mistake is to end it. There is no "fair" or "unfair" in this. If you both want the marriage to survive, that is the only way really.
I dont agree that the way to go is to openly accept the situation and just try to all be happy. No one was on equal footing here. Mr P really seems to be a guy who regretted missing the boat on Mrs 2TT. He got a very unusual and GOLDEN opportunity when this topic of swinging was brought up. I dont expect that Mr P's bond to Mrs. P (which doesnt even seem to have come up) mattered much to him in this. I also expect that if Mrs. 2TT were to say "hey Mr P, screw this... lets run away together", he would do it. That doesnt make for a good play partner or a "poly" situation.
Mrs. 2TT, I can completely understand where this could seem like an amazing opportunity to have both the guy you married and the guy you've always wondered about having missed, but surely you can see that this can't work.
I think for this situation folks have to step outside of some of the usual assumptions and look at this really objectively. It VERY much looks like an essentially vanilla guy who is getting a chance to fix a mistake (never having gone for the girl he loves) I mean really... How quickly did this progress from "ok, lets try swinging!" to "get my wife out of here so I can spend an entire vacation alone with the gal Ive always loved"?
The fact that the feeling is very much mutual is incredibly dangerous.
Mrs. 2TT, a lot of power and responsibility has been placed in your hands really. We dont envy you as it cannot be easy.