"If there's any hope for your marriage you ain't going to fix it without marriage consuleing. I'm a believer in once a cheater; always a cheater."
I agree with your feeling, 100%, though I didn't post it simply because the question about confronting the "other woman" stuck in my craw a bit - I didn't want this poor gal to feel worse if I made mention of it. And, she actually has NO need to feel badly about the stupid decisions that her husband made - of COURSE she cut him out of her life after surrendering their second child!!! This might have been a good time to seek grief counseling, at least.
My concern is that the husband is carting his very young daughter around with him when he's meeting the other woman, presumably as a chaperone. What kind of twisted, pretzel logic is that? Dragging a KID into adult issues and USING said kid to continue his affair? Please...get to a divorce attorney, ASAP. And, get tested for STD's.