Mistress Medea was pissed that her colleague wanted to fuck her. They were friends and colleagues. She did not want to change that so she had to punish him to get that out of his mind. After she tried to talk to him, he continued doing it and that is when she decided to give poop femdom a chance. As he ate her shit, he knew he would never bring that topic up again.
This guy was so good at eating pussy and ass that he made mistress Medea cum while he ate her ass and her poo. She had thought that making him eat her shit would piss him off and he would not be able to make her cum but he braved the shit storm and made her cum in the midst of it all. She felt that the only good thing to do in that situation was to let him smash.
Mistress Mortelle was tired of this guy's miserly ways and she wanted to humiliate him and get him to see some sense. So she went ahead to make him her human toilet. He was degraded like never before and while she felt that that alone would not break him, she knew it would help to start the process of loosening him a little bit. And it worked as she intended it to.