"I want him to be the Wayne Rooney of tennis," said Mrs C, prodding her son Jonas into my infant tennis club. Thoughts of the striker merrily whacking aces into goal amused me as I doled out the bent-framed racquets. "He'll use this," she announced, brandishing an adult-sized, titanium-alloy number at her child. He could barely lift it. It didn't matter - Mrs C wanted success.
To get it, she used every dirty trick in the book. She cheered Jonas's little opponents when they made mistakes and coughed loudly to distract them. Any umpiring decisions she didn't like prompted streams of abuse that would have made McEnroe blush. To chivvy on her unfortunate protege she had a lovely line in motivational speak: "Remember Jonas, second place is first loser." There was even substance misuse - Lucozade in his water bottle.
"She meks me do tenis," he wrote woefully in his diary.
I tried explaining that sport for a six-year-old should be about fun and developing self-confidence - not about making small girls cry and other parents want to batter you.
But dreams of Centre Court, or of one day having a WAG in the family, had blinded her. "Your balls are a disgrace," she stormed the next time Jonas lost a game. I glanced down, checking the Carry On team hadn't entered the hall. But it was my tennis balls' baldness that was impeding Jonas's play, apparently. She had a point - William Hague has more hair - but it was the final straw. I issued the teacher's equivalent of an Asbo: a polite note requesting she ceased coming.
A few weeks passed, then Jonas scribed, "Now she meks me do balay" in his diary. Cue visions of Rooney in a tutu.
The writer is a teacher in South Yorkshire. Send your worst parent stories to firstname.lastname@example.org and you could earn #163;50 in MS vouchers.