First, stop with the blah blah blah... Gabe is just treating me like a FWB blah blah blah. It is simply false. Burn the tape.
Avoidance takes TWO people. Why keep playing the game?
I'm pretty sure I mentioned months ago that the reappearance of OW was almost certain. I've never seen anyone on these boards reconcile without the A partner rearing his/her head multiple times. It was your choice to accept the circumstances and work on an R. What are you going to do now? Quit? Repeat your history so that YOU will have gotten nowhere through this? Why??
I'd suggest a letter:
"Gabe,
Avoidance about your current interaction with OW is not OK here. I agree -- if we are going to move forward in our relationship then we need to get to a place where your past affair does not continue to stress our relationship so much. But, to do this, we need to move forward TOGETHER. "Getting over it," is not something I can do alone.
You were the one who broke our trust. Only with your effort, combined with mine, can we rebuild the trust over time. It will take loving reassurance, rather than defensiveness. It will take honesty, openness and transparency, rather than evasiveness. I think we have a real shot at a wonderful, passionate, happy, committed, monogomous relationship. We can provide a loving and strong family for Marc. We can both become who we want to be as individuals and lovers. If this is something you want to work together on as partners, let me know. Right now, I am open to that possibility.
But, FWIW, I should let you know that I will not be in a romantic relationship with you while you are in contact with OW. I deserve better, and I require better."