I re-read the initial post. The OP had multiple affairs with her husband’s co-workers. It caused the BH a giant amount of pain and rage. He withdrew into himself. He did not divorce the OP, but there has been no physical affection between the two of them for years. Not even kissing. I’m going to assume this means they’ve not had sex with each other for years. They live more or less as roommates who happen to be sort of family and give one another certain types of family-related emotional support and comfort, but no husband/wife sexual/romantic affection.
We don’t know if either of them has had sex with others. The OP said something odd and puzzling:
I genuinely have no issues with him fucking another woman, anymore than he had issues with me fucking other men.
I’m still puzzled by this. Do they have an open marriage?
Per the OP, both of them were more or less okay with this state of things, but then along came the BH’s long lost first love. He has kindled a sexual and romantic love affair with her. OP understands why he is drawn to this. He has been starved of feeling like a desired man since his DDay many years ago. It’s like a drink of water to a man lost in the desert.
The conundrum is that what seemed at first to be a short-term, finite fling with the long lost first love has now become an open-ended relationship that could possibly morph into a serious, committed, monogamous, long-term relationship that may cause the BH to leave the OP. BH has told her that if the long lost first love offers this, he will probably go for it. The OP feels in limbo and wonders what to do. Among other things, she wonders how long she should wait. I gather that the OP would be okay if the BH had a temporary relationship with this other woman, but then ended it and resumed his “loving roommates” relationship with the OP.
First, I want to apologize to IBrokeUs for the harshness of my earlier posts. The nature of these forums is that we sometimes read a post and respond in a snap, without taking time to think through what we are saying. The facts in the OP are strong facts and, as a BH, I was guilty of responding emotionally, based on my personal emotions, rather than in a manner intended to be helpful to the OP.
Second, the undertone to this post is a deep well of love in both directions, possibly informed by a couple who have some spiritual bonds as well, maybe mutual survivors of something. Most BH’s would not reconcile from the original facts, and most wives, even WW’s, would not continue to hang on in a marriage where the husband is openly engaging in a full-on love affair with another woman.
So my answer is going to be based on the notion that there is a deeper level to this couple’s love, a tie that binds.
But the answer to the question is simple. I think the answer to the question is that you stay in the marriage until you don’t want to stay any more. We often warn betrayed spouses here about “Hopium”, but this case is highly unusual. I don’t think IBrokeUs is staying out of “Hopium”. I think she is staying because even though her BH/WH is a shattered man, she loves the fragments and, for now, wants to hang on to as many of them as she can.