Dating again

It's been 2 years since my ex-N and i broke up....He's already remarried...I've not even THOUGHT about dating ANYONE...and i have no intentions on getting serious with anyone for a long, long time to come..But,
if i were to date, what kinds of reactions should I expect from my ex, should he find out? I have no interest on letting him in on my life at all, or trying to make him jealous...those feelings are long since past. I do know that even though he is remarried and always (now) treats me like his enemy, in some warped sort of way he still thinks he owns me. Like a political prisoner or something. I know because he still tries the best he can to attempt to control every aspect of my life, under the guise of "he needs to be in on the decision because it affects the kids"...even on things that don't affect the kids, not direclty anyway.

My ex fiance N (the guy before my ex husband N) hadn't had ANY contact with me for almost two years, and then somehow through the grapevine he found out i was engaged...he looked me up on MySpace, just to contact me and make fun of how my new fiance was "fat". I shut the ex-fiance N down pretty quickly and never heard from him again....

I just wonder what to expect from my ex husband if i start to date again. I know sometimes they'll come back trying to get you back, but i can't imagine that happening with my ex husband because it at least seems on the outside that things are still so new and fresh with his new wife....Not knowing how to respond to him or what he's going to do next causes me the most anxiety out of all of this. the unpredictability of his actions....i know they are EXTREMELY predictable in the framework of narcissism, but well, because i'm not a sociopath and dont naturally think that way, it still catches me by surprise.