Mistress Isabella needed to know that chastity humiliation worked before she could try it on a man she was in a relationship with. That is why she chose to try it out on a slave. She summoned him and she teased him a little to make him receptive then sent him to go and wear it. He did thinking it would make her want to continue messing with her. But he realized it was trap.
Mistress Isabella did not like how her man was looking at other women. She felt that he was a cheating time bomb. And since she did not want that to happen, the mistress chose to make sure that he wore a chastity device so that whenever he did and he was aroused, he would be hurt and humiliated. And after a few times, he felt the sensation of being hurt even though he was not wearing any device.
Isabella Tasci is not your average mistress. She is a mistress who has a practical solution for everything. That is why many people especially mistresses pay her for her services. Today this lady wanted her to get her a solution for her man who liked to sleep with other women. She told her to bring him and when he did, they fitted a chastity device on his dick and he was forced to endure the pain and humiliation of having it.