I taught RE for ten years. That’s a decade of arguing about morality with kids who believe that their right to an opinion excuses them from having to think about their opinions. And then having to show them how to put condoms on dildos – because the government thinks that the only reason STD rates are increasing is because teachers don’t show children how to put them on properly.

Now I teach in a special school I have to admit that the complexity of the arguments has changed somewhat, but their fundamental essence hasn’t. It is perfectly possible to have an argument with a teenager who has a profound communication disability about what you can and cannot play with in the classroom. (Use your imagination – it is worse than you think. And considerably less smutty.)

And while I don’t have to demonstrate condoms any more, it is pretty surprising how difficult it is to fill a balloon with sand – and even more surprising what method works.

Don’t ask what sand-filled balloons are for. You wouldn’t like the answer.