Boys are stupid right?

Ok I need a little outside advice. This year I met a guy at the Ekka, It was pretty cool we spoke like everyday like via msn.msn or phone.I wasn't gonna come up and say hey I really like you but I was suggestive because I knew he felt the same way.Anyway so one day I sign on to find that he loves some chick and they were going out. I felt so betrayed and I just really didn't wanna talk to him again. He was continuously apologising and said " I didn't know you liked me" and I told him he still shouldn't have lead me on if he didn't feel the same. So i tried to not talk to him but he was so persistent that things are the same again. We call each other all the time and he says stuff like I miss you and cute things like that but i wanna say YOU HAVE A GIRLFRIEND and your not treating her right but on the other hand I like being so close to him coz I still feel the same.feel like he should stop coz its disrespectful to me fo making things more than friendly and disrespectful to his girlfriend. I really don't know what to do. We're only sixteen.