You: Hi, (your teacher's name)! I haven't seen you for ages. How's it going?

Your teacher: I'm great, how about you?

Your teacher: I can't believe you're here. What are you doing here?

You: My parents said I could live with my sister and finish high school in this city.

You: Yeah, totally. Yes, of course. It's just... unexpected. You know unexpectedly awesome. uhh Do you want to have a drink..

Your teacher: ummmm i'm sorry, I got a lot of stuff to do so I need to go right now.

You: It's ok. We can reschedule drinks!