He left without saying goodbye. Should I ever ask him why?

This guys I've been seeing for the past 5 months left for college 2 states over. he has barely talked to me all week and I understand he's busy and I haven't been the one to text him first or anything...but he left without saying good bye. should I ever ask him why? or just never talk to him ever again? I don't know I'm really hurt.

well it's not a relationship. the original plan was when he goes off to college we stop talking. but like he made plans to say bye to me. but he didn't.