I am trying to fathom out how a wife and mother who had good morals can suddenly go wayward with no time in-between the transition. While the resentfulness had been brewing for a long time, the transition seemed to happen instantly
The term for this is a tipping point. "[A] tipping point is that moment when a small change tips the balance of a system and brings about a large change;" Her values weren't leading her to happiness--you say there was a long period where resentment grew, and small changes might have delayed or avoided a tip, but once the boat flips it's hard to right. Humans generally don't want to remain unhappy.
When I was a WAH, after leaving my ex-wife, I questioned every value I'd been following, because they led me where I was. In my pursuit of happiness, I adopted a more minimal code of ethics--experimentation, metamorphosis to find self-fulfillment is more apt than downgrade--but some actions were wrong. It took years to rebuild my values system. My values now look little like pre-BD or post-BD.
