The other parent pauses for a few seconds, before feigning excitement.
"Ooh, a camel!" she exclaims, her grin fixed. "My daughter has been cast as Mary."
And, with that, she strides away. You can't see her face, but you can tell by the jaunty way she's walking that her expression is one of immense smugness.
Oh, the joys of nativity. It occurred to me, when standing at the back of the school hall watching the children perform an hour later, that you will find the same five things at every nativity play; and here they are, in no particular order.
1. Costume dramas
Every child's costume is the culmination of weeks of stress on the part of the parent. Where do I get a camel costume from? My child's a dancer, what does he wear? A clown?! Did clowns even exist 2000 years ago?
The reason for such stress is not because you want your child to look good – although that is, of course, a factor. It's because you know full well that every other parent is scanning the stage, making judgements on each child's costume.
That one kid, for example, whose parent has just plonked a tea towel on his head and called him a shepherd. Do her parents not care at all?! But look at that boy, next to her. They've gone a bit overboard on his costume, haven't they? Big show-offs.
A child shouting when delivering their lines is fine; the parents can hear, they're nice and clear, everything's great. But there's always one kid who shouts the words to the Christmas carols, and it's always a boy, and for some reason he always has brown hair.
The bouncy rhythms of 'Jingle Bells' lose their appeal somewhat when a child in the back row is tunelessly yelling each word.
3. The 'whose child is it anyway' game
This is a fairly simple game to play, but is only really enjoyable if you are standing at the back of the audience. It boils down to this: at any one time you can spot the parent of the child who is delivering their lines by how much they bob in their chair and nudge the elderly person next to them. It's like those 'Whack-a-Rat' games you see at fairs: the only thing missing is a mallet.
4. Dancing queen
Every nativity play contains an element of dancing, with very basic steps and hand movements. It's the source of a lot of 'aaahs' from the audience, and is very sweet to watch. But there's always one kid who steals the limelight by losing themselves in the music and jiving like a maniac.
5. Relieved teachers
I have a lot of respect for the poor teachers, who have to try and organise 60 children on stage whilst making sure none of them are being sick or running randomly into the audience.
During the performance you will find them on their knees at the side of the room, gesticulating wildly at the kids, gurning and mouthing the words to those who have forgotten the lyrics.
At the end of the performance, the children walk off stage and out of the hall to rapturous applause. They look relieved; but not half as relieved as the teachers, who can now relax and look forward to their turkey and crackers.