Name: Prom kings.

Age: 16ish.

Appearance: Underage waiter.

Is this something to do with idiots waving around union jacks at the Albert Hall? No, that’s the Last Night of the Proms. This is about the school prom.

That’s an American term. You mean leavers’ disco. Where have you been? The school disco is dead. These days, 95% of UK schools hold US-style proms, generally after GCSEs (or sixth year in Scotland).

What can one expect from this so-called prom? If you’re a student, a tame drinks reception at school followed by dinner and dancing at a hotel or other venue. If you’re a parent, an enormous dent in your wallet.

A pricey night out, is it? Schools tend to keep ticket prices low, but there’s a lot of ancillary spending: hair, flowers, clothes, jewellery, etc. Apparently, girls now spend an average of £220 on their prom night.

Now, I’m not being sexist, but I’m glad I have only sons – 10 Silk Cut and an Uber home should cover it. Boys used to get off lightly, but today’s prom kings spend an average £157 each, up from £131 three years ago.

What could they possibly being using that money for? Suit hire, transportation hire (think limousine), flowers, spray tan …

Sorry, did you say spray tan? Admittedly, only about 6% of boys get a spray tan for the prom – compared with 19% of girls – but 42% of boys have their hair done professionally for the big night.

I’m sick of all these Yank imports. I’ve got grey squirrels on my bird feeder, killer clowns ringing my doorbell and now this. Count yourself lucky you only have to contend with the watered-down UK version. American teens spend an average of £630 on prom night.

A small mercy. Not that you can’t spend that kind of money. Horse-drawn carriages and double-decker buses are popular modes of prom-night transport. For £960, your child can ride to prom in a helicopter.

Why are we talking about this in October? Because you need to start saving now.

Do say: “What do you mean your school doesn’t have a helipad? What do I pay my taxes for?”

Don’t say: “£130 to hire a suit? Think of the drugs you could buy with that!”