DO NOT, I REPEAT, DO NOT PURSUE. If you do, you are a)setting yourself up for being used and discarded, B) allowing him to cake eat c) appearing desperate, which only appeals to his ego. I believe your instinct to go dark is correct, but you are still perhaps having too much interaction with him. Yes, I understand you WANT this interaction, crave it, but you can see it is definitely not good for you or your son.
Absolutely do not stand in the way of his relationship with his son, but that does not include a relationship with you in the bargain. Make him pursue you, and then keep the topics neutral. Avoid the fights at all costs. They are just a way of allowing him to justify his actions in the first place.
