I didn't realize this was your first year
Sorry. I'm assuming you're in a highschool and if it's your first year then maybe don't look much older than many of the students? Principals get very nervous about that - I think because they don't want their school to be next in the headlines. I have a close friend who is very young looking and in the highschool. The prinicpal is hyper-sensitive to her being chummy with the kids at all and she was taking it personally until I (and several others) pointed out to her that what's really going on is he's afraid somebody will cross a line. It does sound like the kids are taking advantage of you a bit. Actually, they were of her as well. Showing up and begging to stay in her room instead of going to a study hall or whatever and she was letting them. We had to tell her, you are insulting the teacher they are supposed to be with when you let these kids hang in your room instead of going to study hall and getting their work done. They would sing her a tale of woe and she fell for it. This is her 3rd year now and she's finally caught on. This isn't a problem I ever had because teaching was a second career for me, but my daughter is a first year teacher and quite attractive. She hasn't had a problem, but her supervising teacher told her that the way she dresses and carries herself the kids can sense she's not one of the gang. She felt like she was being called a snob but I assured her at this stage of the game because of her age, she just can't be chummy with the kids - they'll take advantage and administration gets the jitters. Best of luck!