Mistress Natasha felt that this guy needed to be punished for what he had done and that is why she had to do what she did. She had to use a humiliating way to send him a message and she cruelly did it in a way he had never felt before and a way that he would not forget. The mistress chose to spit on him and that is how he learned his lesson.
Mistress Natasha considered flirting with other girls cheating. But since her boyfriend had not actually slept with other girls, she preferred a lesser punishment for him. But it was humiliating nonetheless as she brushed her teeth into his mouth and she had him swallow it. The mistress was not joking and from the stern look on her face, he had to do what she wanted and do it exactly as she wanted it done.
Mistress Natasha did not want this loser to forget who the boss in the house was. She felt that he was beginning to forget that she was her boss. She reminded him of that fact by humiliating and torturing him as cruelly as she could. She made him swallow her saliva and she brushed her teeth and spat into his mouth. He was degraded but he learned his lesson the cruel way.