Mistress Ludovica Luxury saw disobedience as something she had to fight at all costs. When this guy decided to improvise instead of obey, he ruined her perfect structure. He had tried to throw her off balance and then do things his way, but she was not about to sit back and let him do so. That is why she came up with a way to do what she wanted and be the author of his destiny. So she fed him poo and got him to be a human toilet.
Lady Liana does not like people who do not meet their end of the bargain. When she went to this dentist with a tooth problem, he told her he would easily sort it out but it turned out that he did not. Her issue was not sorted out and she was pissed. She did not want to keep losing money and so she used her shit to dominate him. She made him eat her shit so that he learned never to do that to his patients again.