Madame Marissa wanted her hiking boots licked before she used them to trample the shit out of this slave. She had had enough of him and his behaviors. She had asked him to change many times before but he did not and she had no option but to punish him and so the mistress cruelly ensured that he felt the pain and that he cried and begged her for mercy.
Madame Marissa felt that she had to test the slave's pain threshold because she wanted to teach him a lesson and do it in a way that he would never forget. The mistress knew how to go about it and that is why she used her hiking boots femdom to get what she wanted. And she loved the fact that she got what she wanted at the end of it all.
Madame Marissa needed to test her new hiking boots before she used them. Her slave had just messed up and pissed her off so she had the chance to both punish him and also test out her hiking boots. That is why she did what she had to do and she made him cry as she used the hiking boots to trample him all over his body. It was painful.