David Collings plays Mr Dawlish the headteacher of the local school. Fed up of being cheeked by the Larkin's twin daughters he calls Ma & Pa Larkin in for a chat. He tells them their children are too bright for his school, need discipline & suggests they send their kids to boarding school. This the Larkins do & sub-St. Trinian shenanigans ensue.
Sat on a desk, which amused me.