Why is he being like this? im confused!?

im so confused! this guy and i use to be really good friends, then i started liking him so i told him how i felt , and he told me he didnt really like me like that, well he changed his mind and he started liking me to, so he was the sweetest and he came over and we were about to date, but then he changed to a player, and he said he didnt want a girlfriend, but we were still really good friends, well we had twice and then we got in a fight and now we hardly ever talk to each other. Well i started dating this other guy and i actually look happy now after a year of heartache from the other guy. Well now that other guy , when i try to talk to him he only says like 2 words to me and he doesnt really wanna talk to me, and at school hes always looking at me and my boyfriend, but when i look at him he acts like he aint looking, and he was standing by me and my boyfriend's, friends that we always each lunch with and when we walked up he walked away. why is he being like that? i dont get it.