arbuom,
I must admit that I have thought long and hard about what possible motivation there may have been for your wife to do what she has done. At the risk of asking a bit of boneheaded question, do you think this might be some kind of mid-life crisis? That she suddenly took a look at herself, the marriage, everything, and just thought, "Is this me? Is this what I want? Where am I going" All the kinds of things that hit people in mid-life crisis mode.
What makes me ask that is because whatever the nature of the relationship with the OM was, it seems almost like that whole thing was a by-product or consequence of something else that was going on in your wife's head. That the thing with the OM may have happened because of a mid-life crisis, but that it was not the cause of the MLC, and that even if he is totally out of the picture now, the MLC is continuing to roll on under its own momentum.
That is the 'feel' that I get from everything in your thread. It seems like the OM, such as he was, was more like a welcome distraction for your wife from whatever crisis or malaise she was sinking into, rather than a romantic fixation, and that perhaps what may have appeared to be a romantic fixation on the guy was actually her mental and emotional need for the distraction he provided from whatever issues your wife was having about herself or the marriage.
And now, in the aftermath, does it seem like she is particularly pining for the OM? It doesn't sound like it. So where has the romantic fixation gone? If she was fixated on him, she would now be able to see more of him, so she ought to be happy. Only, she's not happy, is she? If anything, it is like the OM is no longer relevant, as if she no longer needs the distraction he provided from whatever unhappy thoughts were going on in her mind.
It may well be that the OM thought his luck was in, but it's not like this was an exit affair, and your wife had plans to ride into the sunset with the OM. There was never any prospect of doing that, if he is a stay-at-home-Dad, reliant on his wife for everything. If anything, it looks like your wife has collapsed the marriage with no idea of where she is going or what she is doing. Maybe the reality of that 'gap' in her life is finally sinking in now, because it sounds like she is in a sorry state, with no plans at all.
I can see why reading that card from her, and trying to reconcile her words with her subsequently saying she has been unhappy for years makes your head spin. I actually think that she meant those words when she wrote them, but that she has been revising and rewriting the marital history in her head more recently. BS's often get told there have been problems for years by partners who had never said a peep, and seemed perfectly happy for years.
I am starting to see a mid-life crisis as a more likely explanation for the events in your thread than your wife destroying the marriage for the sake of the OM. And that would actually synch with her refusal to say that there was any kind of affair, whether emotional or physical. As I say, I am sure the OM thought he was in luck, and unless he or your wife suddenly fess up, you will never really know the extent that things reached. However, as horrible as his presence was for you, this seems like a different kind of malaise that entered your wife's mind, rather than just an infatuation with someone else. No less devastating for you, but just 'different' from a run-of-the-mill affair.
The other thing I was thinking about was the whole 'revenge' debate. I was thinking that as you have known that couple for a long time, maybe you could just sit down with them and explain what has happened, not in an angry or accusatory way, not blaming anyone, but just explain what has happened between you and your wife so they know your side of things. That is not vengeful, nor is it inviting them to hate the OM. Frame it as just an explanation of your point of view to a pair of old friends who know both you and your wife.
I think it might be cathartic for you to be able to open up to them, and as they know both of you, they will obviously be concerned and surprised by what has happened. The motivation for such an explanation would not be revenge, but rather ensuring that they have an insight into what you have been through, so they can support and understand you as you move forward. I am sure they will want to do that, if they really are friends.
I understand your desire to have a 'cut-off' period, with very limited contact with your wife. I think that will help you a lot, and it will also let her adjust to the new reality that she has created. However, it does look like your wife is not entirely well or healthy. Being apart from you may exacerbate that, and while it could be argued that she has brought everything on herself, you do love her, she is the mother of your kids, and nobody would want her to have some kind of nervous breakdown.
So what I am thinking is that perhaps you could go and see that couple you were going to have the discussion with about the OM, and instead of that, have a long talk with them about everything that has happened, the changes in your wife's behaviour that you have noticed, explain that you need a break from your wife to get your head together, but ask them if they can keep an eye on your wife, because she seems to be in a state of freefall at the moment.
You said that the wife in the couple is good friends with your wife, so she could be a great support to your wife in case she is starting to come a bit unglued. If they are willing to do that, it means your wife would have support, while allowing you to have your much-needed break from her.
As ever, arbuom, please take anything form this that is useful, and leave what is not.
[This message edited by M1965 at 7:06 AM, October 3rd (Tuesday)]