<human>: I have this one teacher at my school that I became *fast* friends with. Hes an art teacher, and I won his heart quickly by drawing him doing funny things, or just doodling silly comics. Either way, he would always cry laughing while looking them over. 

After talking a lot in class I started having lunch with him in his class with one of my friends. We started doing this everyday. We even made up our own language that we would write notes to each other with. 

Out of no where, he stopped talking to me in class. I figured that it would be pretty inappropriate for us to act like best friends all the time, so I didnt mind really..But then he stopped talking to me at lunch. Over all our friendship has just sort of declined. 

I understand that a teacher-student friendship is a tricky thing to have, and he might just be trying to avoid something inappropriate. 
I guess regardless of whether or not we stay friends in high school, I was wondering how I could become his friend when I graduate. Should I visit often? Facebook him? Where do I go from there? I'd really like to just find a way to be friends once there arent any rules about how much we talk.

Could you distill the essence of the text into 1-3 sentences?
<bot>: My teacher is really cool but cant really be my friend due to professional reasons. How do I make friends with him once I graduate?