Mistress BlackDiamoond always knew what to do to her slaves when she wanted them to do something for her. She wanted so extreme that this slave was afraid to do it. It was risky and he had never attempted something like it before. So she made him do it by trampling him using her high heels and making the actual thing loo worse than her trampling so that he could choose to go.
Mistress Lisa wanted to trample her slave as painfully as she could. She thought long and hard about it and she decided to trample him using her skates. She made it as painful as she could and he begged her to forgive him but she did not listen. She wanted him to learn and he learned the hard way. From the on, he never did anything to piss her off.