6. Being Offered Sweets/Homemade Goods From Students
Especially when it's treats freshly pulled from their pockets... without a wrapper. Either kindly decline without gagging or tell them you'll "save it for later".
5. Students Seeing You On A Night Out
Underage students shouting "Miss!" or "Sir!" is not the best look when you're out on the town. Even worse if you're drunker than drunk. We can't wait for the gossip on Monday morning...
4. When You Return To Class After A Substitute
The sub in question smoked ten cigarettes simultaneously on immediate exit of the classroom, and decided to go into hairdressing.