mrplspls,
Situations like yours are always complicated, because they are so different from discovering an affair while it is happening, and making a decision at that point in your lives.
If you could rewind to 1987/1988, and you had discovered the full extent of things, what do you think you would have done?
The reason I ask is because although you have just found out that you survived an affair that you did not realize had happened (until recently), you would like to see if the marriage can be saved and continued. That is no different to people who have just discovered a 'live' affair, and who want to try to reconcile.
The big difference for you is that you cannot break up with your wife as she was back in 1987/1988. You are no longer who you were back then, she is no longer who she was, and you have three decades and children that have occurred after the affair.
Back in the day, you could have decided to stay with your wife in the knowledge of what she had done, or parted with before the relationship went any further.
The thing is, while the knee-jerk reaction to infidelity is to think 'divorce' and 'death to cheaters', the fact is that a lot of people who think they would take the nuclear option if infidelity occurs actually try to reconcile.
So even if we could press a button and zap you back to 1988, you might have been very hurt, but you might have chosen to try and make things work with your wife.
If she could tell you back then that she wanted out of the marriage, and hint about her feelings for her boss, and you turned away from the implications of those revelations, the chances are that you would have tried to reconcile with her back then.
If you pile thirty years of a marriage that you have enjoyed, and the building of a family, on top of that, your decision is not so much, "Do I end the marriage now before anything else bad happens?" as it is, "Do I blow up what I have now because I think I might have done it before I had all this?"
My gut feeling from your story is that your wife may have been too immature to live up to the responsibilities of marriage, and she projected a lot of unwarranted good qualities onto an older man who sold her enough bullshit and snake-oil to get what he wanted before he left town.
And like anyone who has bought into a used-car salesman telling them that the car they want to buy was only used occasionally by a sweet old lady to drive a mile to church every Sunday, it is not so much a clever con-job as a person deluding themselves to an obvious steaming pile of horse-feathers because they want to believe it.
So why did your wife go that route? That is something that she has to answer.
However, even if she was minded to check out of the marriage back in 1987/1988 because she had drunk the kool-aid that her boss offered her, reality kicked her behind in a big way when Superman left town, proving to her that their great 'love' was worth considerably less to him that it was to her.
Do you think that taught her a lesson? Is it possible that she saw how stupid she had been, and that she decided to try and make a go of the marriage and not stray again?
Is it also possible that when she decided to recommit, things evolved over the years into a real and true relationship, even if the affair that preceded it was buried?
People emerge from jail resolved to never go back. What if your wife realized what a mess she had made, and resolved to not do something so dumb again?
Is it coincidence that your wife's idea about leaving the marriage evaporated as soon as her boss left town? It seems to me that she was just a younger woman being played by an older man when she had built him into a fantasy figure that he never was.
When a woman is absorbed in the self-destructive building of a low-life opportunist into Superman, how can a real man compete with that? No man, and no woman, can compete with a delusional fantasy. Unfortunately, countless affairs happen because otherwise sensible people put a rat on a pedestal.
As you struggle to find positives in your situation, I think you should consider that once your wife understood that she had been played for a fool, she wanted the solid reality and honesty that you offered, and that she no longer wanted to look for fool's gold.
The stupid trap she entered willingly thirty years ago should not devalue everything that the two of you have built after that train got derailed. Just as a person walking out of prison can go on to build a solid and worthwhile life, someone who cheats can go on to build a solid and genuine life.
I have said it before, and I will say it again: what the two of you have built together after the affair ended is not false or a lie. It is as real and solid as any other couple who have spent thirty years having kids and getting through life together.
And I would think that all of that adds up to far more of real value and worth than a young woman believing the nonsense peddled by an older opportunist.
Blowing things up at this point will not change what happened back then, but it will impact on your future, your wife's future, and your kids' futures. It will not impact on your wife's AP at all.
So ask yourself if parting with your wife is going to achieve anything of any benefit for you or those you love, or if it will be a pyrrhic victory that costs you more more than it costs the AP.
It seems like the past thirty years have been good prior to your discovery of the affair, and that will only have happened because you and your wife get on well and want to be together.
Is it possible that parting with your wife now could prevent more years of what you have had for the past thirty years, while changing nothing that happened back in the 1980s?
If so, it is worth sticking together and toughing it out. It is not easy, and it is not fast, but if it both of you want it, you can make it work. Unless you have a burning urge to call it quits and go, it is worth trying reconciliation and seeing how it goes.