Kevin, It really sucks - I don't know that my W is having a PA, but I'm pretty sure. I, personally, would prefer not knowing the details. All they do is consume your mind, honestly...
I did want to pop in here with you - you have asked me before why I was doing divorce, etc, and I don't know if I ever responded.
I will file divorce soon, unless clearly checked by God. The Bible, and Jesus' own words give me that option, and it was what I need to do. I will sit down with my kids, and show them Jesus' words, and I will tell them that I don't want it.
Then I will file.
Now, I want you to know - I pray EVERY DAY, multiple times a day for W's emotional healing, for her salvation, for our family. I pray for protection for my kids' minds. I pray for me to be the father/husband/man I should be. I have not given up on our relationship or our marriage. I have simply realized that there is probably a reason Jesus gave the option he did.
I would take W back - no questions asked. I don't care what her relationship with OM was - I know it wasn't "her". I would have two requirements: 1. A full STD check 2. Absolutely no contact in any way with OM - a single text would result in divorce
Obviously she would need medication or counseling or both.
You are in an amazingly hard place - there is this horrible part of us that likes to watch horror movies - that same part I think reads those emails. You can allow it to destroy you and sicken you to the point where you diminish your wife to an animal.
Sexual sin seems so much dirtier and harder to forgive - because giving ourselves in making love should be a sacred thing. But, based on what you've said, I don't think your W gives two hoots about this person - just a weird fetish.
Protect your rights - don't squander anything because you are trying to be "nice".