Lady Melody needed to humiliate this guy and she did it to send a message that mistreating her was not ok. She did not want to imagine what he did to other people who could not defend themselves and so she cruelly trampled him hard and she head crushed him. He was in pain and realized that he was paying for all that he had been doing to others. He kept quiet and took his deserved punishment.
Mistress Rea and Roberta wanted to dominate this guy as they did not like him. And so they got him to their house and used their boots to dominate him. It was easy to get him to their house as he assumed that the hot and naughty mistresses wanted to have some fun with him but that is not how it went down. They turned him into a boot slave and he had to lick their boots to avoid being trampled by them.