When a married man meets another woman and they hit it off, the reason is because of his wife. See, he’s not just himself, but her as well. His mannerisms changed when they married and his personality changed, everything about him changes when he marries. So the other woman sees not just him, but her as well.
So what happens? He meets new woman. He is taught from the time he’s a child that a man can only love one woman, so he knows he loves the second woman, so what does he do? He goes silent. He hides it. Not because he’s dishonest, but because he has no clue on how to act. His mind, his hormones, and his education has betrayed him. He is lost, hurting, and angry and scared, and at odds with himself because he has no idea how to act or manage this situation. The other woman and he finally bangbang and then he’s trying to figure out how to get out of his mess. Trust me, I know. He then does something really stupid and expected. He leaves his wife. Not because he no longer loves her, but because he’s been taught he doesn’t love her. Think about this a little while. Do you know that this monogamy only idea is so new in human history that it’s barely a baby in the grand scheme of things. There’s no tradition, no education other than, “MAN BAD. SUFFER! DIE!”
So he leaves his wife. Moves into the new woman’s life. But there’s a problem.
See, he starts to quickly change. He’s no longer the same man, he changes to be a combination of the new woman and himself. The issue? The new woman doesn’t LIKE herself. That’s why she’s looking for a man. That’s why she chose him, because he was him, and her, even if she didn’t realize it at the time. Now, he’s changing, and she doesn’t like it one bit.
I give it a year. Possibly two if they are stubborn.
Now, here’s what SHOULD have happened.
He meets new woman. He likes her. He tells his wife about her. “Hey, honey, I met a woman that seems really nice. I want you to meet her.” He now has protections. They may, in the future, decide to bring the second woman into the household, and if they do, then that’s great. But leaving his wife for her is off the table unless his wife is childish and envious. This is how it was done for thousands and thousands of years until a very bad actor decided to change things.