When this mistress needed to teach her landlord a lesson, she knew that the best way to do so was to hit him where he least expected her to. So she turned him on as he had a thing for her. The mistress waited for him to be naked before she crushed his balls and his dick with her sneakers. That is how he learned his lesson the painful and hard way.
When mistress Zephy wanted to find out what this guy's pain threshold was, she had to trample him and crush him all over his body and that is what she did. She did not care what he felt as her objective was to find out how much he could take. The mistress enjoyed herself at his expense and she was able to get the info that she wanted at the end of it all.
Lady Miriam called her slave to where she was and she punished him by trampling him. She used a scapegoat to punish him because she felt like punishing him but she did not have a concrete reason. She humiliated him and tortured him by crushing his balls using her bare feet. It was a lot of fun and she enjoyed it and forgot she was supposed to fake being angry.