I suspect many fathers would quake at the prospect of being the comically diminutive dad-doorman at their Year 11 daughter’s post-exams, post-prom party in early July.

But I am perfectly happy with the idea. I back the post-prom party - and maybe even a post-post-prom party. It may mean a potentially bloody face-off with surly, uninvited young drunks, or wandering into the darker corners of the premises with a fixed, avuncular smile, effectively in role as some form of human contraceptive. But if it means our daughter and her friends dance a few more hours of value out of their witheringly high-priced prom dresses, it’s got to be worth it.

I am told that, despite its extreme cost, a prom dress is often a “one-wear-only” item. I am mindful to change all that. To squeeze even more return out of it, I might even start wearing it myself, maybe to our own school’s ball. I may not come across as Gatsby, but he and I would share at least one thing in common - we’re both now secretly penniless.

My students should be equally unsurprised if they later see that same dress bundled together and reincarnated as my all-in-one board-wiper, wasp-catcher and draft-excluder. I might use it to give the allotment scarecrow an overdue upgrade. That Gove outfit looks weathered these days.

Until my own daughter’s coming of prom age, I had no real knowledge about the dresses. Apart from not having a clue about the initial cost of a frock, I had no idea that shops run another highly lucrative sideline in “taking the dress up” for the buyer, raising the price up another £50 to £100. The longer dresses seem to have been bespoke-made for some mythical 7ft Amazonian, so “taking up” is an inevitability for most.

The only thing I already knew about those shops was that they boast an electronic database, aiming to ensure no two students ever wear the same dress. But the system does not seem to allow for the odd rogue teacher-customer. Last year, a student at our own school’s prom literally went head over heels when she saw her science teacher mum-dancing in the same bud-green number.

Being completely miserable and puritanical about this American import, we could point out that the average-sized secondary school could probably pay for a full-time teacher and TA with the money spent on prom dresses alone each year. Although I can’t imagine redirecting the funds would go down well with the punters and their parents, even in these dire financial times.

Besides, I saw my daughter in her (taken-up) dress for the very first time yesterday. A cliché, yes, but you cannot put a price on how amazing a daughter looks at such times (certainly more than £182). On the surface, the buying of that dress may have made me colder and more cynical about the world of prom, but - deep down - I suspect it may have done the very opposite.

Stephen Petty is head of humanities at Lord Williams’s School in Thame, Oxfordshire