After this transition, can the man be trusted not to go through that again? I think you're right about the "idealization" of the other woman.
I found a sappy, adolescent-sounding poem my husband had written about hearing the other woman's voice for the first time. (They had met online). He waxed poetic about the sweetness of her voice saying his name.
I was floored! He is one of the least sappy men in the world, and he would be the first to make fun of someone else who had written a similar sentiment. I just wanted to throw up when I found it.
It made me relive the moments when I first found out he had left me, and when I found out (he didn't tell me) about the other woman.