No stop sign, so I'll post my thoughts. I've followed your posts so far and here's my general perspective.
I find it difficult to reconcile the idea of loving someone with engaging in an affair. While many claim it's possible, I simply cannot understand it. To me, loving someone means protecting them fiercely. The thought of inflicting what's almost universally considered one of the most painful betrayals imaginable is fundamentally at odds with my understanding of love.
Perhaps it's a difference in our definitions of love, or perhaps logical thought is muted during psychological distress. I don't have a definitive answer.
However, I do have some insight into what are often termed "revenge affairs," having read and written extensively on the topic. What your partner did could potentially be classified as a revenge affair, though it's debatable whether it even counts as an "affair" given that your partner reportedly considered themselves single and you were separated at the time.
What's clear is that they likely wouldn't have slept with someone else if you hadn't done so first. Therefore, I don't see you as a victim of anything other than your own actions. It's a simple case of cause and effect, much like someone who punches another receiving little sympathy when they're punched back in response.
From your latest correspondence, it seems your partner desires a divorce and wishes you well. This is a remarkably positive outcome, and you should view it as such. When I was cheated on, I spent years hoping my ex and the person they were with would suffer terrible luck and lives. The fact that you've managed to part on relatively good terms is a tremendous advantage.
I'm personally skeptical of forgiveness and the general success rates of reconciliation after infidelity; the statistics on this aren't particularly clear. However, you appear to have received a significant gift in the form of what seems like forgiveness. You should be content with that.
I'd strongly encourage you to use this opportunity for self-improvement. Focus on understanding how to avoid repeating similar actions in future relationships, or, if you feel you can't reach that point, make peace with the idea of being on your own.
I'm not sure how much this will help, I've never been in your shoes. Can't even imagine it. Your partner deserves a fresh chance at life without someone who's betrayed them. You deserve a relationship untainted with betrayal. Make peace knowing that. The biggest cliche in the world but I do think it holds true here. If you love them, let them go. I wouldn't want my worse enemy tied unhappily to their own betrayer. If you love them as you say, let them find loyality.
