Thanks for the reply Oldwounds. I dont think I was clear enough in my post, sorry....there are many parts he understands.
Circumstances...
We were long distance at the time, and he made decisions back then based on "him" and not "us". This is changed now and he'd never be away from me again.
He didn't understand what an EA was so he became what he thought was "friends" with this woman when really it was a kind of EA. This has also changed, he basically just doesn't want any kind of intimacy with any woman ever again unless it's me.
There was a great deal of alcohol involved. That's changed, he completely stopped drinking.
The AP was infatuated with him, and he was susceptible to it and confused feelings of being persued with being valuable. That's changed too, he sees now that his value is something he makes for himself not from outside validation.
He was intimacy avoidant so he enjoyed having a split in his life where he could have me but also a split life of his own. This was the hardest to change bit it 100% has and now he lives life transparently,as partners.
He was fundamentally deeply selfish. That has also been really hard work to change but I think he worked very hard at it and now is selfless in many, many ways.
So we had huge progress and I can't imagine it being possible that he'd ever make choices like that again. That said I do not trust 100% but if anything ever worries me, no matter how minor, he just listens and resolves it.
What he doesn't understand is his myriad of awful behaviour during R. For example breaking NC, putting APs feelings over mine at times, missing the A after it was over... that sort if thing. He really doesn't understand it.
The A was a friendship turned sexual that wasn't romantic in nature, but once it did turn sexual the AP wanted him to leave me very quickly and when he refused she became abusive and violent.
I am understating there really, she was very violent and very, very emotionally abusive which gave him PTSD, so he just wasn't ever able to understand why he kept defending her, even as she was being abusive, or why he kept talking to her or missing her. He just says he wasn't in his right mind.
So I do still find myself having mind movies or loops of thoughts. There was fog for sure at that time because it took him a very long time to step out of it and truly get how bad it was. I think, my perspective, was that for a long time after D Day he was still thinking of just himself.
All that said, he's changed completely. I just wonder if you can put things to bed without ever fully understanding all of it.