What would you do.

So me and my ex were dating on and off for a year and now that we broke up (we broke up like 2 mo ago) he always posts on SC that I broke his heart and he misses me and I'm the worst and blah blah. But yet when I see him in public and speak and say hi or whatever he acts as if I'm not there. It pisses me off and I'm trying to act like the bigger person or whatever. But I also want to confront him and tell him how I don't like what he's doing. But idk. Pls help.