At our primary the Christmas show takes place on three consecutive mornings to accommodate everyone. The format is fairly fixed. Nursery first for two songs, then a couple of numbers each from primaries four, five, six and seven with a little extra something from the choir or music group.
The big finish is the nativity with primaries one, two and three providing the traditional cast of angels, sheep, kings and so on. Full spectrum of dressing gowns, tea-towels and tabards on show.
We all know we don't really have much interest in the bits that don't have our children in them, however cute and well-rehearsed they are. Harsh, but true.
But what boils my blood every year is the sight of parents getting up and leaving the school hall as soon as their kids' bit is over. This causes a disturbance and means that later performing children are faced by empty seats.
We're all busy and doing important jobs. Do you not think I haven't got a million better things to do than watch other people's kids fidgeting and lisping their way through We Wish You A Merry Christmas?
However, I - and the other better-mannered parents - sit there til the end. We do it because it shows respect for the children and their hard work, the school, the other parents.
How can we expect our offspring to learn about manners, respect and civic duty if they aren't surrounded by examples of it? It's a fairly important lesson that when you say you're going to do something you do it until the end.
You departing parents (and there were more dads who left than mums) must know that the rest of us all just as likely to be bored, fed up and numb of bum. We're sitting there thinking of the things we should be getting on with too, writing lists in our heads and itching to check our phones.
So next year, for the sake of all our children (and my blood pressure) just sit still. It's an hour an a half out of your life once a year.
That was the ninth Christmas show at our primary and, all things being equal, I'm likely to attend another eight before Boy Three graduates to secondary. This, if nothing else, qualifies me to pass judgement.