Help with ex boyfriend!!?

I met his at the rollordrome and I fell for him. We made out and all that crap. He said he loved me until we stopped texting. For no reason. Now I may see him this Friday or not then I'll see him in the fall in school and was wondering what I should say to him. He's a good kisser has good looks and I really do like him. Now only answer how you would handle this situation if it was you. Not no good up to him say hi and smile crap please. Maybe flirting or trying to make him jealous and dirty dancing to the loud music? Btw I'm 12 and am mature. So don't say I'm too young and focus on your studies. I do so please answer my question. If your nice enough I'll give you 10 points