Lady Scarlet had a bet with this guy and she won it. She decided to trample him as a result and she did not care what he felt. She had won and so he had to handle the consequences of losing. He was lucky she did not pee or poop on him or even make him give her money. She even told him to thank her when she was done trampling him.
Lady Scarlet wanted her husband to workout and be fitter and healthier but he did not want. She knew what risks his lifestyle posed and she had to make sure he changed. So the mistress wore her sneakers and she used them to trample him and make it so painful that he would not have a choice except to work out the way she wanted him to. And that is how it happened.