Do teachers gossip about their students?

yes. a lot of students have reputations.

Yea teachers talk about funny thing students do dumb things even to other students

No teachters can not talk ill,about there students. Maybe ur teacher was asking another teacher that has been in there situation.

I think it depends on the teacher, but they all have guidelines to go by. If a student is in some kind of need of help, or shares something personal, most will not UNLESS they need a second opinon, and that will not include making fun of the student, unless the teacher is just a jerk.
Most are not. Don't worry , I m sure your confidence is kept, and you could just ask....