“The tawse has a really harsh sting,” says Belinda Lawson after the long leather strap lashes across her jiggling bare buttocks. “When Earl Grey made me count off the strokes, I realised my voice was going up and up. I wasn’t acting, it hurt!” Bent bare bottomed over a gym vault, on her toes, Belinda’s Reform Academy lesson is harsh. Reaction Cam and slow-mo replay show every cheek-rippling, teeth-gritting moment.