Mistress Zephy was out to make sure that this guy learned never to mess with her again and so she had to scare the shit out of him. That was done by cruelly turning him into a foot slave and having him lick as well as smell her socks and her shoes. He was shocked by what she did to him but he was too scared to say anything about it.
Mistress Zephy wanted to dominate her boyfriend because she had caught him cheating on her. The mistress felt that the best way to deal with him was to turn him into a foot slave and let the humiliation get to him. If it did not work out, then she would dump him. But she had to make sure he learned his lesson both financially and through humiliation. She put her plan in motion.
Mistress Zephy did not like how slow her slave was and she had to put an end to it. Since she had talked to him about it but he did not change, she felt that the best thing to do to him was to teach him a lesson. That is why she opted to sit on his balls and on his crotch while making him lick her smelly feet. The humiliation made him change.
Mistress Zephy wanted her ass to be eaten and that is why she chose to facesit this loser. She started by trampling him to make him cooperate. And then she went ahead to make him let her facesit him. It was after this that she made him lick her asshole as she was not wearing any underwear. He knew better than to disobey her so he did what she asked.