This mistress found out her slave had poor oral hygiene and tried to tell him what to do to make it better. She did not do what she told him. He did nothing about it and she was pissed. When she realized it, she punished him by facesitting on him. She did it with a dirty ass and compared it with his mouth. She made him promise to do something about it if he did not want further punishment.
This mistress wanted to show her boyfriend that she was not happy with that he had done. She did not like how he assumed that everything was fine and tried to brush off her concerns. She had to do something about it and she did. She forced him to lie down and she facesat on him. She ass smothered him till he nearly choked. That was when he understood there was a problem.