Imagine the average staffroom. Are you reminded of Meg Ryan's fake orgasm in When Harry Met Sally?
No? And yet, listen carefully as you imagine the following scenario. In a dark, evil-smelling corner is the cover noticeboard. A teacher approaches it cautiously. It's Tuesday. She's got two valuable free periods, yet every Tuesday this year she's been put down for cover at least once. Her gaze sweeps over the sheet, searching for her initials. As it does, little sounds escape from her lips. The first is an intake of breath. Then a "Yes!" Period 2's safe. Her finger traces across the paper to make sure.
What about period 8? She inhales again, then issues a triumphant "Yes! Yes! Yes!" as she realises she's escaped.
She throws back her head, laughing, and punches the air. What can hurt her now? Let Kylie ask a thousand times for more paper. Let Jimmy scratch his initials on a nearby locker, and let Jake stab fellow pupils with a rusty compass. Let the whole class leap out of a second-floor window one by one if they want to. She's got her two free periods and that's all that matters.
At my independent school, where we are still obliged to cover for absent colleagues, I pass an entertaining 10 minutes before registration watching the daily cover-board parade. Some, like the female teacher I've described, react publicly and with great delight at finding they've got away with it.
Like Meg Ryan, they want everyone to share their ecstasy.
Some make all the same movements but in silence, more like Charlie Chaplin.
All the drama is there; they just prefer a more private moment of jubilation. There's a dignity in this approach. Others, though, keep ramrod-still as they survey the board, their emotions controlled, body movements kept to a minimum. But as they turn, there's a faint flush to the cheeks, a brightness in the eyes - like a costume-drama consumptive - that betrays them. They may even do the little cough - "Ahem" - to show us all that they are not perturbed.
But what if the news isn't good? Then we have our expressive, emotional, female teacher yelling "No! No! No!" - like an anti-Meg, in the throes of despair. She thumps a desk, throws a pen, glares at her fellow teachers and storms off to the senior teacher responsible for this outrage.
Our Charlie Chaplin falls to his knees with hands clenched in isolated grief. The flush on his cheeks is a little redder, his eyes a little brighter and there will be three "Ahems" this time, but he will keep it under control. He will do his duty with a stiff upper lip, just as he did "in the war".
I pick up my coffee cup and approach the board. It's a tense moment, a hiatus. And then I remember: I have an eight-period day today and two registrations, so no cover for me. I turn, disappointed. Covering a nice Year 7 silent-reading class would have been a bonus today. There's just no pleasing some people.
Fran Hill teaches in Richmond upon Thames