Mistress Nica wanted to teach her disobedient slave a lesson and she did it by forcing him to lick her dirty boots. He had messed up with the wrong person and he regretted why he had taken her for granted. He was now being made to lick her boots and to also endure her trampling of him with the same dirty boots he had licked just a few minutes earlier.
Mistress Nica is not the kind of person to piss off as this slave came to learn the hard way. She did not get mad. She just punished him so that whatever he did would not happen again. The mistress used her boots to trample him. She also removed her boots and got her socks and her bare feet dirty then had him lick them all clean. He learned his lesson.