Mistress Barbara's slave needed to be reminded who was boss in that house. It was like he had forgotten and she had to remind her. She did so by ballbusting him. She tied him up and then had an easy time crushing his balls. Not only did she nut break him, but she also used nipple clamps on him. Everything was excruciating for him but that is how she wanted it.
Mistress Barbara and her slave agreed that he had messed up. He knew he had to be punished but he did not know how she would punish him. She ordered him to undress and when he had done that, she tied him before she crushed his balls with her hands. She told him he was lucky she did not use her high heels. But to him that was not a consolation as it was still very painful.