Mistress Darcia had to make sure that her ex learned that she had moved on and wanted nothing to do with him. That is why the mistress made sure that he learned his lesson and would not piss her off again. He was trampled, kicked and made to lick her feet. Her feet were muddy to make it even more humiliating for the guy. He had no choice but to do it.
Mistress Electra needed to torture this guy and she did it with her worms. The mistress had to make sure that he learned that she was not to be messed with and was rather to be obeyed at all times. That is why the mistress chose to trample him and to make him lick mud and worms from her feet. The guy had no choice but to do it all.