Getty
Teenage girls are lucky.
If they get a spot, they can zap on a bit of make-up. Boys don't usually understand cosmetics so don't have that option.
But whether or not you whip out the concealer, a rash of spots (or just one huge great angry boil) can ruin your day.
"Can you see it?" says my daughter.
"What?"
"This!" says my daughter, pointing at her face.
I stare hard.
"New mascara?" I say.
"You're just trying to make me feel better," she says.
I do remember it – that teenage conviction that everyone's staring at you, itemising all your faults. It makes you very defensive.
I was on a bus recently in a grey fog of exhaustion, idly looking out of the window, and a boy of about 16 thought I was being critical and shot me a look of malevolent fury.
But people don't actually look at each other that closely. You have to do something really dramatic like shave your head or pierce your nose before people notice anything different.
So, as a parent, your job is to show that you understand the horrible self-consciousness that skin eruptions bring while, at the same time, offering reassurance that no one's really looking.
Admittedly, some teenagers get it really bad.
My friend's son had horrible acne from the age of about 13 to well after he finished university. He had antibiotics from the GP, lotions, creams, the lot. But nothing made any difference.
When I saw him the other day, though, his skin was clear. The raging storm was over. There he was, tall and good-looking with a huge great smile. Like a young Will Smith.
And yes, I admit it, I did stare then.