You've been through teen love and heartache. can someone just give me some advice?

ok so this guy and i have been playing with each others emotions for years now. he likes me and i like him but we wont make a move with each other. dont ask why. but he still talks to other girls and they hug him and etc. now dont get me wrong i talk to guys but when he talks to girls and i see it, it hurts so bad. so why does it hurt? we dont go together.and im pretty sure when he sees me with other boys it doesnt hurt him because sometmes i watch him and when he sees me with another boy he keeps going like he doesnt care. so how can i stop feeling like crap when ever i see him wth other girls? i mean its obvious he doesnt like me cause he hasnt made a move so anyways how can i stop the pain??