He confuses me, i need all the advice and answers i can get =/?

okay so there is this boy i like, ive only knew him for a little while but he is in my cl at school, well he knows i like him and everything, and we talk all the time about random stuff and we always laugh with each other and stuff, he already has a gf but he acts like he likes me a lot, there is this other girl in my cl that he flirts with and they usually act silly and funny together but everytime me and him gets around each other and start talking we get into long conversations and we dont act silly a lot just some, i got my other friend to ask him if he would ever go out with me and he said nooooo!! but he randomly smiles at me all the time and like i said flirts with me.. how can i tell if he likes me?, since he already knows i likes him, but all my friends always tell me that when a boy says he doesnt like you and says ewww about going out with you then that usually means he likes you..so i need help..REALLY BAD!!