Why do I miss him :(

I miss my ex sometimes even though he dumped me. But the reason I think is that his best mate still talks 2 me on msn about him and I act like I dont care at all and I have moved on, but when some girl hit me he was the first person 2 ring me and I turned around and said 2 his mate why did he ring me? and he just said he really want to talk to you. I have not spoke 2 him in 3 weeks and he thinks I have moved on. I do think about him sometimes but his mate found out I am going the cinema 2moz with a lad and he sent me a link 2 the first film me and my ex watched :( and I just cryed his mate keeps sayin how are you and these lads and I will be like we are fine:) I act as if everythin is fine but I know its not :( I have changed since me and my ex have spilt up 4 the best I just want 2 show him that but I am scared 2 do it. when I last saw him he keep starin at me what is that meant 2 mean?I dont think you can just stop lovin someone I just wish he would realises what was infront of him. me and him cant be mates we never can, I asked him why he blocked me on msn and he turned around and said because I deleted his number he deleted my msn

please help me xx