This mistress was out to torture this guy and she did it with her armpits. The mistress knew how to not only make someone feel pain, but also how to degrade them. And she did this by trampling the guy and later on using her sweaty armpits to degrade him. He could not talk as he was afraid of saying something that would offend her and make her punish him some more.
Mistress Zephy wanted to dominate this slave for being a nuisance to her and she did it with her armpit femdom. The mistress made the guy lick her sweaty armpits and she laughed at him when he tried to refuse. She told him while smiling that she would do worse things to him and if he knew what was best for him, he had to lick her sweaty armpits. He did.