See Me At Four Girl.

In her last term at secondary school, my wife had to report to her Headmistress after school. She had caused the breakage of a corridor window and her Headmistress wanted to see her.
The Headmistress had been teaching and used a classroom as a base. Sue my wife made her way to the room and looked in, seeing the Headmistress sitting writing she knocked the door and was told to enter.
After a while the Headmistress stopped writing, looked up and started giving a lecture. After she had droned on and on about her behaviour she said to Sue "I'm fed up of seeing you before me, well I'm going to slipper you"
and fetched out a punishment book from her desk draw. She told Sue to fetch a chair, while she entered the details in the book, Sue placed the chair in front of the Headmistresses desk and waited.
The book was replaced and the Headmistress walked over to a cupboard, unlocked it and fetched out her slipper. The sole was that of a well worn plimsoll but the top was the same as a mule slipper and the Headmistress took great delight in waving it in Sue's face, as she gave another lecture.
The Headmistress told Sue to bend over the chair and when she was satified with her position she lifted up the back of her pleated skirt, Sue found this uncomfortable as it seemed to take quite a while and started to wriggle, the Headmistress told her to keep still or she would get an extra stroke.
The Headmistress placed her hand in the small of Sue's back and gave her three hard whacks across her knickers, sue jumped at every stroke.