Confusing ex boyfriend advice?

last year i went out with this guy.. we always wrote notes in cl but he had a gf and he was basically cheating on her. so he broke up with her and everyone would ask him why he broke up with her but he'd just look and smile at me.. so we started going out and a few days later he broke up with me and started going out with his ex again! and he wrote " i miss you notes" to me then broke up with her and asked me out again, and me being gullible fell for it and we went out again. but by then summer was a few days away, he broke up with me again and i found out he cheated on me with some girl he met AT THE MALL! then this year started up & we got started again, then the day he was going to ask me out he asked some other girl out. i simply then gave up on him. he still keeps talking to me and i told him it doesnt bother me but it does, he still flirts with me but he's a player. he wont stop! he's even befriended my brother and he talks about me with him and makes me sound bad. uh help?!