Hmmm, something to think about. I had a feeling he was looking for an OW prior to this OW. He made some complimentary comments to an old friend, recently D, on FB and hid his comments from me... it sent up red flags at the time. Then he met this OW at the HS reunion and kept their communications private from me. He was looking for an A, in my retrospective mind. Oddly enough, by examining his behavior, I think he was looking for an OW but it was not conscious, if that makes sense. He hid the seeking behaviors from me and somehow explained them away to himself so he didn't feel like a louse just stepping outside the M for an A. It was like he was driven to find an OW and this one just stepped in and filled the shoes.
There was no trigger, then, that I know of. Other than him turning 40 and being so very tied in his mind to youth and not wanting to admit that he was getting older, always saying "it's how old you feel" and stuff like that.
The lack of a trigger was one of the things that made me suspect this was not MLC for so long.
He never dropped the bomb, I snooped and found the bomb (OW) and then he came out and said he never loved me, I controlled him, everything was my fault, etc.
No one died, no one got ill, no accidents, no job loss. Nothing changed other than our finances pooping the bed, if you will. And his oldest going to college and then dropping out and staying home.
Mostly it was the loss of our love... due to neglect, that I think did it. H is a HUGE romantic and believes the Hollywood version of love, and will not see anything from the experts at all. He thinks he knows what he's talking about and they do not... that love just happens, it stays forever and if it doesn't, it wasn't meant to be. You can't work to get love back once it's gone... now, mind you, this is all MLC talk. He was open before to the 5LLs etc but now says it's all bunk and junk. He told me that he should not have to tell me how to make him happy, it should just happen and if it doesn't, it wasn't meant to be between us.
Anyway, we were one of those really in-love couples for a very long time and having the kids come live with us back in 2005, when just recovering from his EA at the time, threw us into one very big, long neglectful state of our M. I think the loss of our love was such a shock to him, he thought it would continue forever just without any effort. He never saw the effort I put into it, I guess, and just thought it just "happened" the way it does in Hollyweird.