I'm sure Labug will be back soon with some words of wisdom. I just wanted to let you know that I totally get where you are coming from in your wish to know what was really going on during those years.
I feel that too. No one likes to feel like a big chunk of their life was a mystery story. I've actually fantasized that someday, maybe when we're grandparents, STBX will actually spill about everything.
I tried asking once, but of course I don't believe the answers. I don't think he's capable of honesty about things that make him feel bad about himself right now. And frankly, he's always had a rotten memory, which is convenient for him at the moment, and of course his definition of "affair" is probably different from mine. I want to know when the first one started, before or after the kids and I left Iowa. He says after, but I'm pretty sure there was at least an EA going on, because I well remember the sudden and striking change in tone and behavior towards me. It matters to me because he was the one that came up with the plan for the girls and I to leave first while he remained behind. If he did that intentionally so that he could carry on his affair with ease, it would really alter my whole view of who he is, because it would have been such a deliberate, planned, thoughtful act of betrayal.
I don't mean to be a downer - but I don't think you or I will ever get the level of honesty we are looking for. Mostly because, I doubt they are even honest with themselves. It's a burden, and we can either toss it off or let it weigh us down.