How do I handle my Ex-Boyfriend at a party without him ruining it for me?

i'm 16 also and trust me, almost every 16 year old boy is immature. actually EVERY boy is immature no matter what age. this boy is no different and it sounds like he was never ready for a serious commitment. but really at 16 years old you should be having fun and just hanging with your girls and date some boys, but keep an open mind. forget him (: you can go and do whatever you want and no boy can stop you.