you work hard all year to build up that impervious veneer of cool, that imposing sense of authority - and it can disappear in the turn of a page.
Teachers across the country can be forgiven for sneaking a glimpse each month at that bible for teenage girls, Bliss. Among the make-up tips, celebrity fashions and true-life horror stories, the magazine has a feature called "Humiliate your Teacher", a chance for pupils to get their own back with snaps of Sir or Miss in compromising positions.
Step forward, Mr Taylor of Robert Pattinson school in Lincoln. The German teacher insists on being called Herr Schneider and makes kids sing carols auf Deutsch. He thinks Stephen Gately is a pupil in another class and sports an alarming moustache.
Hats off to cross-dressing Mr Garbett! The art and music teacher from Spalding High in Lincolnshire is captured resplendent in a purple wig and fur coat at a vicars and tarts party.
And congratulations Theresa Smith, PE teacher of Sherwood Hall Upper in Mansfield! Her punishment for forcing the girls to do football is to appear before 300,000-plus readers wearing a joker's outfit which she inexplicably donned during a school skiing trip. That'll teach her.
Actually the victims come off pretty well compared to the stars of Bliss's other regular snapshot feature, Embarrassing Parents, a column which prompts the questions: how do these people sleep at night? And why were they allowed to have children? The letter that accompanies a gurning Mr Woodward from St Paul's School in Bletchley gives the game away. Pupils Channell and Sherry confess he's "actually a brilliant teacher". That must make him feel so much better as he squirms.
"We haven't had any saying 'this teacher is really horrible'," says editor Liz Nice. "It's always the opposite. It's always for a laugh." In other words, it's the ultimate accolade. Which may be some consolation to Mrs Curtis of Fairfield High in Bristol, captured with the register looking particularly stern. Or to Mr Wilkinson, of Reigate, who thinks he's David Beckham and has been seen in, ahem, leather trousers.
After all, it could be worse. They could have appeared in the Biddy Watch feature (grumbles about interfering old folk) or - gulp - in the "I Fancy You" column, where readers confess their secret crushes.
Liz Nice isn't sure how teachers react when they see their mugs in her magazine, but she admits: "I've got a friend who's a teacher, and she says if she ever appears, I'm dead."