Goddess Wu wanted to punish this guy because he was disinterested. She did not want to work with such a person as she did not want that habit or his feelings to rub off on other people. She had to torture him and she did it with her hot ass. She had him eat her poo as well as drink her pee. He also had to lick her asshole clean.
When mistress Zhan was cheated on, the first thought was to cheat as well. But for her it was not as simple. She could not bring herself to do it and so she had to come up with an alternative punishment for her boyfriend. After thinking about it, she felt that shitting on him was the next best alternative and she did not hesitate to use it to punish the shocked boyfriend.
Mistress Fan did not want to be the only one who enjoyed shitting on guys. She knew that it was much more fun if it was something that she had in common with other girls and they could plan parties and fun activities around it. So the mistress taught one of her friends and she got her to love it after she had gotten her to give it a try.