Shopping for underwear in Mamp;S my teacher radar senses movement behind me, then hears the all-familiar refrain "Awright Miss?" Year 9 pupils snigger as I inwardly struggle with yet another invasion of my private life, and simultaneously hide a pair of French knickers behind my back.
Such incidents are an occupational hazard for teachers. Every day activities become a potential minefield of public exposure and humiliation.
It is bad enough when those embarrassing moments happen at school, like having to wear a borrowed cardigan tied around your waist all day when the seam of your trousers splits open.
Opportunities to blush do not stop at the classroom door. Travelling to school by bicycle is an endless source of crisis. Usually I try to arrive early, yet there always seems to be a pupil lurking to witness a personal predicament.
Once, after being cut up by White Van Man, I let out a stream of expletives, only to hear a voice say primly: "You told us not to use slang to express ourselves, Miss."
But it is those off-duty moments that can be the most dangerous, such as the end-of-term faculty social. On one occasion Miss M and I, having rendezvoused at the station, were laughing raucously when we spotted a group of children waving at us. Dressed in festive glitter with too high heels and skirts too short, we stared disbelievingly as they approached. To add to the humiliation, they were with their parents.
It is hard to look professional with musical reindeer antlers bobbing on your head but we gave it our best shot. Coming home the gods conspired against us yet again as we fell off the pavement while hailing a cab.
"Awright then, Miss?" emerged from the shadows like silent paparazzi.
Those celebrities who court fame and then complain about their privacy being invaded should try teaching sometimes.