A radiator key is a wonderful implement. For one thing, it allows you remove excess air from your radiators and therefore enable them to produce the maximum amount of heat, which has undoubtedly saved many a pensioner from death by hypothermia.

But in the hands of a group of 10 year old schoolboys intent on mischief, a radiator key can do much much more. We found out that we could lock toilet cubicle doors from the outside using this tool. Naturally, we proceeded to do so at every available opportunity. For two whole weeks the scandal went on. How would the powers-that-be respond to the crisis? Eventually, an assembly was called to address the situation.

"People are locking cubicles from the inside and climbing over, rendering them unusable," barked the headmaster, clearly quite annoyed at the ongoing disruption to toilet usage. A select few, of course, knew different.

A few days after the assembly, it all came to a head. We were midway through securing a toilet door yet again in the boys changing rooms, when in burst the headmaster and the sports teacher in what was no doubt a meticulously planned ambush.

In their excitement the sports teacher proclaimed "Ah ha, Headmaster, we've caught the toilet mountaineers in the act!"

We couldn’t help laughing at this ridiculous exclamation from Mr Dresser. Neither could the headmaster. It took some time before order was restored.

Eventually, however, the toilet mountaineers were banged to rights. Fortunately, when they sent a letter home detailing the whole sordid tale, my mum thought it was funny too.

I'm letting this one go because I like it, but if anyone can explain to me exactly how you can lock a toilet door from the outside using a radiator key, please let me know. If it's possible, there's going to be some toilet mountaineering at my workplace, make no mistake. - Matt