Mistress BlackDiamoond needed to show her friends how to punish and especially how to fist. They wanted to dominate this loser and they did it in a way that he would never forget. He was shocked by the brutality of what they did to him but the mistresses did not care as they had gotten to a point that he had to be dominated as well as degraded by the mistresses.
Mistress BlackDiamoond did not feel like this lesbian was doing the right thing. She had to remind her to do the right thing which was for her to stop masturbating. She did not want her to get addicted to it as it was not a good thing for her to do. That is why she chose to make her lick her feet and degraded her while asking her to masturbate at the same time.
Mistress BlackDiamoond had seen how her lesbian slave was checking out her ass and she knew that the slave admired her and wanted to have sex with her. But instead of doing that with the slave, she made the slave lick her ass. She had no choice but to do what the mistress had ordered her to do. Funny enough, both of them had a great time although for different reasons.
Mistress BlackDiamoond wanted info from this girl and she could tell she was very curious sexually. So she exploited that weakness and she got the girl to try some naughty things she had never tried before. She was turned on like never before and she got an orgasm she had never had before and she was dying for more. That is how she told mistress BlackDiamoond what she wanted to know.