Mistress Gaia and her friend wanted to torture this guy because he had not done things to their expectations. The mistresses felt that the best thing to do to him was to humiliate him and that is why they went out of their way to trample him with their riding boots. He also had to lick the soles of their boots before they were done with him and let him go.
Mistress Courtney did not like how defiant this loser was. She felt that she had to teach him a lesson so she did it in a way he did not anticipate. The mistress felt that she the pain would talk to him better than anything else would. And so she stomped on him to make sure he stopped being defiant and by the time she was done, she was sure he would not do it again.