Your situation isn't like everyone else's. You're not dealing with a WS who's just been busted. You're not even dealing with the same person who committed the offense. Thirty years changes people. Your W has thirty years invested in this marriage, same as you. So, on one side of the scales, you have an early adultery but on the other, three decades of love and dedication. You begin to see how easy it might be to invalidate those many years of devotion.
MrPlsPls - above is a very interesting take on your dilemma - I guess if you want to adopt this point of view, well then, what are you bellyaching about? It was so long ago!
Of course, this assumes that somebody who cheated on you repeatedly and multiple times even with a hiatus in between, during what most would consider to be the "honeymoon stage" of your married life then subsequently deceived you for 33 years is being truthful about anything else.
But let us assume this "good time accrued" point of view is valid. What about you? You've got 30+ years faithful! Do you get to fuck somebody outside of your marriage now and say - "Well, just look at all the years I have been good! Don't get hung up on this little thing and ruin our investment."
By the way, that would be a wrong thing to do.
The other assumption is that the investment of someone who cheated so early on in the marriage, then subsequently lied about it, is equivalent to the investment of someone who has been true and faithful the entire relationship.
That cannot be true. The whole point of the lie is to obscure the lack of investment, and to deny you the agency to decide if you want to invest in a life with this person.
It ain't the same.
What you might not understand is a woman's reaction to that kind of invalidation. What you're saying essentially is "I don't care about your thirty year investment. All I care about is this lie". And that's okay, if that's truly what you mean. If so, file for divorce and move on. But if those thirty years had value for you as well, you'll want to get into counseling together and avoid taking advice meant for newly betrayed BS's. In that advice, we come out strong without care to the survival of the marriage because if our WS doesn't change, the marriage doesn't matter anyway. Your WS has ALREADY changed. She needs to be handled differently if this marriage still matters to you.
MrPlsPls - It is not your job to be understanding a cheater and liar's unhappiness to your consternation at their cheating and lying even if that person is a woman - and I am not sure why gender makes it any different by the way?
If your therapist or psychologist tries to sell you this line of reasoning, please move on to another one, quickly.
By the way, you are a newly betrayed spouse! What counts is when you learn of the cheating, not the moment when the cheating occurred. Lying for years then stating "It was so long ago, but now I am different, are you going to throw it all away?" is straight out of the cheater-speak playbook, and I am shocked to see it being utilized in the Surviving Infidelity Just Found Out forum.
It appears this entire argument quoted above puts all the onus on you! It assumes your wife's honesty and virtue for 30 years (Regardless of 30 years of deceit), it pressures you to "get over it" because it was so long ago and "she changed" which is entirely made up conjecture, and it encourages you to rugsweep because you are only focused on "The lie" (No mention of the extramarital sex).
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Let me give you some good solid advice that works for newly betrayed as well as long-betrayed spouses: GET THE TRUTH FIRST! Then you can start processing that information and making your decisions.
Good luck to you.