Ageography teacher of considerable competence and experience was left deflated after a senior male pupil asked to be excused during "an interesting lesson on inner-city landscapes" and returned with his hair rearranged and gelled.
The boy admitted that he had asked to be excused because his hair wasn't quite right and that this was distracting him from what was a useful, interesting lesson.
It has become more common for male pupils to fret about their appearance. There is now, according to traditionalists, too much touching of hair-gelled quiffs, furtive applications of lip-butters and adjustments to earrings and other bling.
"Some boys now carry hairbrushes and sprays," one experienced practitioner lamented, "and they use all sorts of facial oils and makeup. It's that Justin Bieber's fault."
Such an analysis may lack the accuracy and tolerance we have come to expect from senior practitioners, but it highlights a trend that is causing some to despair.
Responses from what has traditionally been the fairer sex have been mixed. Some senior girls have spoken appreciatively of well-groomed male pupils. But the group of S4 girls I recently overhead castigated male grooming with words and imagery I could never repeat in this journal.
Young male teachers, it is reckoned, are also spending too much time on clothes, hair and accessories such as man-bags.
But female teachers have not been supportive of male colleagues with a penchant for grooming. When a local authority's "well-being at work" initiative was extended to include subsidised facials, eyebrow-plucking and manicures during term-time, female teachers were annoyed to find that the most convenient appointments had been seized by their male colleagues.
Personally, I am not offended by the fashion for male grooming, and phenomena such as "guylashes". Young people see footballers and actors dressing more creatively, so why not teachers too?
We have been fortunate to witness the rise of the alpha female, so why not also this new type of well-groomed male? There must be opposition to any form of discrimination based on appearance.
And I applaud those schoolboy debaters, unafraid to wear pink, who recently made a strong defence of male grooming which they cleverly developed into an argument in support of male liberation.
So we must accept the hair-gelled quiffs and the new mannish fragrances, but we must draw lines, for the protection of academic standards, to ensure our lessons are not interrupted by texts from beauty salons or, indeed, requests for "hair breaks".