Just remembered about an infamous pupil at inverurie academy, Graham Milne, aka "fool"
We had an open plan English department, each class was separated by screens ,these things were around 5 ft, high, with material on the outside , a gap at the bottom, and two metal stands, they were standard issue in schools those days.
Anyway , as our English teacher Mr Cockburn ( nicknamed fanny freeze) , went sit at his desk, fool had crouched down, on the other side of the screen, in an adjoining class, and as fanny freeze went to sit down, he pulled the chair from under him, , look you should've been there, as the c**t, got back up incandescent he barged through a gap in the screens and asked , who was that?,
To which fool replied whilst still holding the chair " wasn't fucking me"