I just discovered this and am really grateful for the focus on LTA issues. Here is my story. I'll try to keep it short. My D-day was in Jan, and we are in MC right now. My WS's affair was with an ex from college. They were pretty serious for at least a year and a half in college, maybe two. Then she cheated on him. He was still an undergrad and she graduated and had started a high status professional program and cheated on him with another person in her program.
Officially I know they had a lunch with a mutual friend before our youngest was born (and before her 4th kid was born) and were in casual contact via email and phone. On my own, I discovered so much more. Since 2014 she had moved--in a way I discovered on my own--to a location that allowed them to see each other frequently thru work travel. And I now see evidence she had been in our home town at least twice while I was away with the kids. It's pretty bad: years of repeated lying and also messed up manipulating in which work trips I went on with him or he went on with me included days on his own before or after spent with her. It's completely gutting. And of course all this I discovered after denial, misdirection/manipulation, and trickle-truthing.
Once I found out enough I asked him to separate and was getting my ducks in a row to follow through. He then gave me a heart-felt speech with a blanket apology for not putting me and our family first, that we are the most important things to him, etc. and asked to do MC and bought us a few books to read, took responsibility for fairly frequent negative everyday behavior over the last few years (not surprising given that he was justifying his affair to himself, or comparing me negatively to a person I didn't know was in his life). I agreed to work on things, but made it clear we couldn't rugsweep whatever had happened.
Now we are in MC, having addressed conflict/repair and underlying relationship issues for a little while. In our latest session I brought the affair front and center finally. I have told WS multiple times I wasn't going to wait forever to address the affair, and highlighted the Esther Perel "building a shared story" and reinventing your marriage kinds of questions I wanted answers to. I even gave him an advance head's up I would be bringing it up in our MC session, which he didn't fight (he just seemed sad to face it). I was so kind to him and everything, knowing it would be hard for him. Then in the session itself he goes on and on about how he doesn't want to talk about it, doesn't think it will help, doesn't trust me because of how I've dug up info on him, thinks I won't believe anything he says. I could have killed him, and also wanted to be swallowed up in a hole since I didn't think he was still this entrenched. The therapist just focused on our empathizing with each other, and made the two paths clear to him: that if we don't talk about it, it's a dealbreaker for me. If we do talk about it, it could make things worse or could save the marriage.
But my other dealbreaker is no contact and transparency which I don't have. My WS has done a 180 in terms of how he treats me and the kids, and has been 100% transparent in his daily activities and has gotten out of all future work travel that would put him near his AP. He's also no longer denying there was an affair, but there is zero transparency with email, computer, cell records, etc. and he's guarded with his phone all the time. So my main worry is that I can't tell if he's backburnering his ex and is still in contact, or if he's just delusional thinking he's hiding evidence of stuff I already know happened.
FOr more context, his AP is married & will not leave her high status husband due to money, won't work full time and move to be with my WS even though she could, etc. and prob doesn't want to because it will disrupt her kids' lives and also make it harder for her to be a hard core status-seeker for their college futures. I think she'd like my WH to get a divorce to continue their affair, which her husband doesn't know about (he's a workaholic). This means she sees no problem disrupting our kids' lives as if they don't count as much as hers. What a piece of work.
Their favorite movie was Serendipity so their affair fog narrative was clearly that they are destined to be together, despite the fact that they never lived together in college, that neither relationship, then or now, is infidelity free, that there is zero chance he would ever want to be a stepparent to her kids or actually be a good one, that she is trading one workaholic spouse for another, that he's got health problems she likely has no clue about, etc. My mind says this is not real love but a LTA with an ex you actually did have a relationship with does worry me a lot. A lot. I'm worried I'm going to be backburnered till all our kids are off to college.
I know there is deep shame, and my WH comes from a family with deep shame, his mother was critical and his dad emotionally unpredictable. So he's got few emotional skills. But I think I should cut and run if he can't talk about this stuff soon.