“Hey, what’s his new girlfriend like?” my friend Nicole asked me about her son, who just happened to be in my form.

“Can you get us a picture off the records? He won’t bring her home. Have a look what sort of grades she’s getting.”

My jaw fell open. I assumed that would convey my shock to her but it clearly didn’t.

“You’ve got to be kidding. I can’t and don’t want to be involved in anything like that. Data is strictly confidential, Nicole.”

“Well, just a little photo.”

“No, nothing.”

Nicole did not get the principle of confidentiality. Neither did she seem to understand that her son, who was 16, needed to decide for himself what his mother knew about his life. I decided to steer all future conversations away from school, but she would ring me at the slightest sniff of gossip involving staff or pupils.

It reached the stage where I had to check I never got tipsy on a night out with her as I knew she would be straight in there looking for an indiscretion. She never got the hint and never gave up.

I decided she needed to be taught a lesson and that I would feed her little bits of disinformation to add to the effect. I would pretend to remember suddenly that I shouldn’t be saying such things.

Choosing a story to fabricate was difficult. I consulted a couple of colleagues. We didn’t want to bring the school into disrepute or involve students. We decided to make a story up about Gemma, the art teacher, who readily agreed.

But I had not realised the true depth of Nicole’s ability to pry into other people’s business. My ringing mobile woke me after I had gone to bed early one night. “Hey,” said Nicole. “I hear that art teacher at your school is ...”

Nicole filled me in on all the details from our proposed gossip before it had even started. Trust Nicole to have a mole in my close group of school friends. I should have known better.

The writer is a secondary teacher.