My brother are I are hand-jiving to Bonnie Tyler in the front seats of the Skoda while we wait for a red light to change. We deem it a tribute when we see that two men in an adjacent white van are filming us on their mobiles. The 11-year-old ignores their beaming appreciation. 'Mum,' she shrieks sobbingly, 'You are EMBARRASSING!'
I have always known that there are two certainties about motherhood. One is the guilt that roots itself in the maternal heart from the moment you meet the gaze of your newborn; the other is the embarrassment that your existence causes them as soon as they start school.
I perpetually mortify my children with my wonky red beret, my fastidious consonants, my attachment to pen and ink and my tendency to extract the life stories of check-out staff. My daughter dies a little inside each time I wear wellies to the school gate. My son ducks out of sight when I try a headstand in the vestry.
What I didn't expect - and what my offspring fail to realise - is how they, in turn, undermine my matronly dignity. When they shut a stranger's arm in a cafe's freezer chest I cower. When they barge old ladies out of the door of Cancer Research, ask what a virgin is during a gospel reading and scratch their undercarriage in the Communion queue, I feel myself diminished.
Sadly, recalling my hot flushes when my mother lodges complaints in restaurants, I realise that this is a torment that is not cured by age. Generations gaze at each other, cringing, across a chasm, and the more like our mothers we become the greater the discomfort they can cause us.
As a treat I agree to buy the 11-year-old a take-away pizza from down the road. I command her to remove the make-up she has layered on, mortified at the thought that people will judge me. She, meanwhile, frets over her own reputation. 'Have you ever been to Dominos Pizza before? ' she asks. 'Never,' I reply. She turns on me a scrubbed face full of reproach. 'Oh my gosh, Mum,' she cries, 'How EMBARRASSING!'
Do you embarrass your children? Or do they embarrass you?