I need help with a guy, whats the matter with him?

so i lked this one guy but i wasn't all over him, but at the same time i hinted that i lked him, so he knew that i did, but time ped and he and i stayed friends, so i moved on, i dint lke him anymore, but wen word started to get around that i didn't lke him anymore, he started to act strange, he would avoid me, and wen i would want to talk to him he would go off and start talking to some one else, it was lke he was mad at me, i didnt get it. but my sister said that he was staring at me, but wen i would turn his way he would look the other way or start talking to someone, so my question is, why is he acting lke this? he and i were really good friends.