Is it normal that my ex-boyfriend is this way?

My ex-boyfriend and I broke up a little over two years ago. I try not to have anything to do with him if I can help it. However, on Facebook he would I.M. me whenever we would be on at the same time. He kept saying things like me being "sexy" and "one of the hottest girls in the church." He would tell me he would date me again if he could (of course I was not interested in him). The thing is, my ex would do it when he had other girlfriends (one of which happens to be good friends with me). I kept pointing out to him that he needed to stop because he already had a girlfriend. He claimed he was not hitting on me but I think he was. He did the same to my friend (while with his current girlfriend) and she eventually un-friended him on Facebook. I told him to quit stalking me and un-friended him on Facebook too but he keeps trying to add me back. He would also text me and tell me he was "sorry for everything he did to me." (In the past he would apologize to me but then act like a jerk again.) One of my other friends had I.M.-ed me and tried to get me to be friends with him and I told her I didn't trust him. Is it normal that he acts this way? Maybe he's never gotten over me?