This is usually how it goes when you’re dealing with a guy who has you as his main chick, but won’t make you his one and only. He doesn’t do these things because he is a terrible person. Instead, he behaves this way in your relationship because you’ve shown him that you’ll put up with just about anything. A man can only get away with what you allow him to.
As for me, once I removed myself from my position in that tumultuous relationship, I didn’t look back. There is so much more to life than being a man’s doormat, and that’s precisely what the main chick is. I do think about my ex from time to time and wonder what woman he is making miserable now, but I would never deal with a guy like that again. Zebras don’t change their stripes, you know?