Goddess Nastya needed to shit on this guy because he was wild. The mistress needed to make sure that she taught him a lesson that he would never forget and she went ahead to make him eat her poo and drink her pee. She did not let him off the hook until she was done with him. He got the message and he changed like she wanted him to do.
Goddess Nastya did not want anyone to give her the silent treatment. She did not like it and had to punish this guy for trying it. She felt that it was unhealthy and that things had to change. That is why she went out of her way to degrade the guy and make sure that he learned his lesson the hard as well as cruel way. He never gave anyone the silent treatment again.
Goddess Nastya had an issue with this guy and it was because he was an inconsiderate piece of shit. The mistress had to put an end to that and this was done by forcing him to eat her shit and drink her pee as well. As he did that, he realized that it was easier for him to be considerate than to eat the mistress' shit and drink her pee.