Katrin wears a pair of knee-high softboots with heels and teaches her slave the laanguage of these boots.
She steps and walks on his body, the boots are soft, but with thin heels and Katrin like to checkout the limits of her slave.
She let the heels sink deep in his skin, leaving many deep marks. She steps also on his hands, maybe cracking some thin fingerbones and hey: there is a face, ready for to be destroyed under the nice heels.