Was my teacher right to say I was being "rude" before class?

I got to class early the other day, and there were some other students sitting down. i sat for about five minutes, and got up to go to the cafeteria to get a drink. Somebody else got up, and I didn't hold the door open for them. When I got back they were already there, and he looked at me and I said "lol.. who the ****ing hell are you? the king?" After class, the teacher told me that he heard of this incident, and that I should not be "rude" to classmates after that point. Was I being "rude"? The way I see it, it was deserved, nobody is obligated to others.

Put the internet to work for you. via Personal Recipe 2629979