It really gets to be a situation where you know everything you do will be a fight, so you stop doing things you'd normally do to appease the other person. But they're never happy. It doesn't matter how much you give of yourself, it's never good enough. I always felt so blindsided when his feelings were hurt because I walked on eggshells all day every day to avoid "hurting his feelings", but it simply could not be avoided because it was how he manipulated me. He had to have an excuse to further isolate me - so no amount of walking on eggshells would have ever kept him happy. That's how it works.

And yes, it's very slow. If they were like that from the beginning no one would ever fall for it.