Lady Nora and her friend mistress Kim were betrayed by this guy. That was not acceptable and the guy had to be punished for what he had done. He had to be taught a lesson, and the mistress chose to do it in a way that she was sure the guy would never forget. She spat on him and she made him cry. He wished that he would not mess with her ever again.
Lady Nora and her friend were fed up with how boring this guy was and they had to torture him for all that he did. The mistresses chose to use their spit to torture and to degrade the guy so that it would make him find a way to be more interesting. They felt that if they did not do it, he would not have any incentive to change and he had to.
Lady Nora does not like two faced people and when she noticed that this guy was one, she had to punish him for it and she had to dominate him. She did not want anything to do with him as she knew that she could not trust him. So she did what she does best and she used her spit to degrade him and to make sure that he was humiliated by drinking her spit.
Lady Nora did not want this guy to think that he could do whatever he wanted. She had to scare him and had to make sure that she scared the shit out of him. That is why she chose to use her spit on him. As she forced him to endure her saliva, she also ensured that he licked her spit and that he swallowed it before she let him go.