Why does my ex call me annoying if I don't bother him?

[MACnuggets♥]

I really don't understand how it's been a while now and my ex boyfriend still has such strong bitterness and resentment towards me since we broke up
I leave him alone since knowing he doesn't want to be on good terms, I don't look in his direction, I don't talk to his friends or family, I blocked him on all social media so he doesn't have to see my stuff, deleted all our pictures together, made it clear I will stay out of his life.
And I guess blocking doesn't work because sometimes he'd see my stuff anyway online and had the nerve to text my friends to tell me I'm annoying because he saw something I posted or heard a made up rumor I wanted to get back?
But why does it bother him so much?
It does go into depth but I'll just leave it at that. His birthday was coming and I personally face to face talked to him after so many months and told him Happy Birthday and I still cared and he listened to me and seemed fine. I'm so confused.

[mario-fan-1]

I had the same exact problem a few months ago. Your ex really wants you back, he's just mad at you because he knows that you might not feel the same way, so every time he sees you he remembers and gets upset and angry. So he bothers you to try to get your attention. But when you guys have a nice talk like when you told him happy birthday he might have liked it because he got your attention in a good way. He only wants to be with you, he misses you. I wish you the best, hope it all goes well (: