Bent over a chair, bottom totally bare, Belinda Lawson has just been spanked, watched by Helen Stephens. Now Mr Johnson selects a wide wooden yardstick to test her reactions to a wooden implement - and Reaction Cam is there to capture every moment. See cheek-rippling slow-motion replays as Belinda struggles to stand on tiptoe at The Institute .

Bent over a chair, bottom totally bare, Belinda Lawson has just been spanked, watched by Helen Stephens. Now Mr Johnson selects a wide wooden yardstick to test her reactions to a wooden implement - and Reaction Cam is there to capture every moment. See cheek-rippling slow-motion replays as Belinda struggles to stand on tiptoe at The Institute .