If you asked any of my students at school, or any former students what my pet peeve is, they would tell you EYE ROLLING! I cannot stand this-- I view it as a complete show of disrespect. I'm not a fan of students arguing with me, or speaking in a hateful tone-- but I can usually handle that better than if they roll their eyes.
5 Other pet peeves:
Leaving dirty dishes in the sink and on the counter instead of loading the dishwasher.
People who ALWAYS talk about themselves.
Selfishness in adults.
Chewing gum like a cow chewing cud.
People who will not even attempt to be flexible. (Especially fellow teachers)