What does he have against me?

[Christina]

My ex boyfriend dumped me over 6 months ago due to the fact, that I refused to have sex with him. I told him throughout relationship that I wanted to remain a virgin until I was ready, which he couldn't cope with. After he broke up with me, I deleted him off my fb and cut all contact with him. I didn't want him to see that I was actually hurt about the breakup, so I pretended like it didn't get to me. Shortly afterwards however my ex started tweeting very rude things about me and posted indirect posts about me on his blog. I continued to ignore it. He even sent him a 'mistaken' text message.
About 4 weeks ago, he posted 'How to piss off a girl? Tell her to call your ex gf for advice on how to give a *******'. I know for a fact, that he reads my tweets on twitter, as he recently mentioned the same thing which I did the next day. I honestly can't understand why he keeps posting such insults about me, when he's the one who broke up with me? There should be no reason for him to be so vindictive.

I have started seeing someone else and I have moved on. But the fact, that he continues to write such things about me irritates me.