I really do know that I have to get rid of my insecurities surrounding Swiss Miss (and insecurities in general). But I do disagree somewhat with what you say as it applies to her popping up in our lives.
Most experts on infidelity say the A partner SHOULD share any correspondence with the OP, and I’m hoping the T will say that to him. I can agree not to freak out if he can just be open about this, and at least share his intentions about where he expects this "friendship" to go, and NOT share with her anything bad about our R.
Shirley Glass talks about this, NOT sharing the sad details of your R with the OP – it sends a signal that he MAY be available, and in our case he did it over and over, making it much easier for her to slither closer to him as our problems grew. I know I have to get rid of the monster, but just writing this one off as a “random person cropping up in our lives” doesn’t work for me – it’s only been 4 months since they spoke, and he wasn't even able to tell her we were back together!
As SD put it on my thread many moons ago, there's a difference between old boyfriends and girlfriends whose Rs with S. and I ended on appropriate terms. Case in point, one of my ex-BFs is one of my best friends today, and S. and I visited him and his fiance in Miami last year. The two of them (S. and my ex) hit it off like old war buddies! But Swiss Miss is someone who has actively disrespected our R, and any correspondence from S. is reinforcing that it's OK to do that.
I'd love to hear other thoughts on this, as I'm sure they are widely varied in opinion. As always, Betsey, I'm really listening to you.