I was expecting a challenge when I accepted a post at an inner-city school in a demanding Year 6 class. What I didn’t expect was that a parent would be one of my new pupils. Yet here I was, standing in front of the class, with a father and son sitting in front of me.

It had been the headteacher’s conception; the answer to this boy’s difficult behaviour. The school had used up all its ideas for behaviour modification. Positive re-enforcement hadn’t worked and the headteacher was anxious not to go down the road of suspension and expulsion. It was generally believed that with the support of the father in the classroom, the son’s aggressive behaviour would improve.

He lived alone with his dad. His mother had left when he was four, apparently believing that the best way to depart was to leave her son on a bus to ride around until it was realised that this little one had been left unattended like a piece of luggage. The father had spent the intervening years trying to make up for the experience.

Every example of the child’s antisocial behaviour was met by his dad’s kind, understanding but ineffectual response. So here were father and son, doing spelling tests. The son had a better understanding. We moved on to mental maths but the boy decided to have an outburst and said: “I’m not fucking doing that.” His dad replied: “Oh son, I was looking forward to that.”

The writer is a class teacher from Portsmouth.