Lady Nightfrozen had loaned this guy some money but he did not want to pay her back. She had to get her money back because the guy had overstayed with it. She knew she had to force him to pay it and she used her strapon to do it. It was a lot of fun for her and she had a great time forcing the guy to pay her back.
This guy needed to be punished and this mistress was able and willing to do it. She did not want him to think that he was untouchable and that is why she went out of her way to use her heels to trample him. First of all, she told him what she wanted to do before she went ahead to do it and she ensured that he was not just humiliated, but in pain as well.