Help!

Jennifer

Im 13 and i REALLY like this guy we tried talking for a while but when his ex girlfriend found out he "coincidentally" stop liking me we are best friends still but it kills me every day when he talks to me about other girls I don't want to tell him this because I enjoy the fact that he feels like he can tell me stuff but I love him so much and I have for the past four years how do I make him fall for me?