The school prom is meant to be a gateway to adulthood. It’s the moment when the formless blocks of humanity you have been shaping into grown-ups with the hammer and chisel of education are thrust into the wider world.

Yet when you arrive at that hotel venue just off the ring road, where the carpet smells of toilets and the lights have been dimmed so you can’t see the damp, the students you see are more Morph than Michelangelo’s David.

This is because the school prom is not, in fact, a celebration of progression but a portal of regression. Your pupils may well appear to be responsible pre-adults in class, but put them in a white limo and it acts as Doc Brown’s DeLorean, sending them back to the earliest stages of their lives, the days of illicit treats, tears, unstable friendships and the dressing-up box.

It’s an early years mentality with a teenage capability. Instead of smuggled chocolate biscuits, they have “water” bottles full of vodka; rather than holding hands on the reading mat, they’re indulging in inappropriate public displays of affection in the darkest recesses of the function room.

Teachers understandably find this a difficult situation to police, as Caroline Ross says in her feature in Professional this week. She writes of seeking out snogging couples with a large torch and suggesting some time out and a glass of water to the inebriated.

Ostensibly, the school rules still apply at the prom and parents’ expectations of behaviour are unchanged, but trying to ensure compliance must be like attempting to block out the sun with a hairnet. So should teachers just abandon the pretence altogether and let students get on with it? Of course not. The impact of a watchful eye and a quiet word may end up being invaluable.

Above all, though, teachers should try not to judge their charges. Young people today are arguably under greater pressure than any previous generation. We test them more than ever and expect them to make decisions about who and what they want to be at an increasingly early age. Is it any wonder they long for the freedom of their early youth?

And it is normal for 16-year-olds to test the boundaries, to experiment and to make bad decisions. That is how they learn. Of course we should try to stop them making mistakes, but if they do they should not by tarnished by their error for ever. Instead, we must simply ensure that they understand what they have done wrong.

Admittedly, this is easier said than done. We are a hypocritical species. I mutter angrily at teenagers being drunk and disorderly in the same streets where once I lay in a gutter feeling very ill indeed. Worse still, that gutter is not entirely foreign to me even today.

It is these experiences teachers must call on during prom night. Do your best to thwart misdemeanours, but remember your own mistakes before you judge students too harshly for theirs.

jon.severs@tes.co.uk