Not knowing what country you live in, I would go straight to your Principle or who ever is in authority and tell them right away. This not right and against the law here in the U.S. Tell your parents and let them deal with it also! But make sure you tell someone right away!
So I'm 16 & am in High School and my weight lifting teacher constantly flirts with me. When I'm walking by him to get to another place in the school he always talks to me and calls me by my full name because he knows I dislike it. What do I do?
It's okay for teachers to talk to their students. In fact, most students prefer teachers who can have a joke with them - it makes the lessons more fun, so they respect the teacher more and end up doing more work and learning more! Is it possible you're misreading the signals?