Princess Kitty did not like the way this guy had been behaving. She felt that it was up to her to teach him a lesson and she did this in a way that he had never experienced before. He was turned into a sneaker slave and he had to endure all that she did to him. It was painful and brutal but she did not care about any of it.
Mistress Tatjana does not like dealing with unreliable people and this guy was one such person. She was not going to let him off the hook and that is why she chose to trample the shit out of him. The mistress made sure that he felt pain and that he was degraded before she warned him never to be unreliable again if he did not want to feel that pain again.