Okay, on the topic of why they don't catch themselves before they go off the cliff, here are my thoughts.
First of all, typically men leave to something. Words from my MC. They find something that excites them in a way that of course we wives are not doing. One major area being sex, of course. But in addition to that, it's probably a playmate who has similar interests, not as much baggage, etc...
For women, while I agree that many will leave the M before having the A, many do not. And I think it's because it just happens. All of the sudden, they're getting something their H has not been giving them.
They don't stop themselves because they are just following their feelings. Before they know it, they're in the throws of a passionate love affair and needs are being met that they didn't realize haven't been met at home. I the case of my H, I don't think he realized how "unhappy" he was in our M until OW came along and sparked somethign in him... something that I was simply not doing.
What's the right thing to do? Get away from the temptation of potential affair partner and go home and discuss it with your spose. But IMO, that takes a very strong, emotionally intelligent person to do that. And most of the spouses who fall pray to the affairs are emotionally unaware. So, here they are, comletely "in love" and ready to throw it all away.
Married 9 years Kids 5 and 6 Bomb 2006 H back and forth for a year M now back on track
