Lady Scarlet was misdiagnosed and treated for an ailment she did not have. And when it came to light, she was so pissed and she had to make sure it never happened again. She looked for the doctor responsible and she trampled him cruelly. She was doing it for herself and for other patients because she wanted him to be more careful when conducting investigations into his patients. He became more careful.
Lady Scarlet was bored and she needed to have a little fun and she chose to have it at the expense of this loser. The mistress wore revealing clothes and she knew they would be turned on by the sight of her hot ass and her nice tits. That is how she managed to get them to do what she wanted which was to let her trample them for fun.
When lady Scarlet learned that this old loser was dishonest, she was torn between forgiving him and punishing him. She asked her friend for advice and her friend felt that they needed to make an honest man out of him by punishing him. And that is what they did by trampling him with their bare feet. He was in a lot of pain and his age did not help him as he had thought it would.