Mistress Zephy used chastity femdom to degrade her boyfriend. She was doing it because they used to have a lot of fights about cheating or messing with girls and she was ready to quit. He begged her not to and she agreed. He did not realize that she had a trick up her sleeve and he was shocked when she pulled it off. He had to lick her ass and her asshole before being made to wear a chastity device.
Mistress Zephy knew that her husband did not like to keep it in his pants and so she had to control him in a way he did not expect. So she teased him while they were in the bed and he was turned on and was malleable to her. She then got him to wear a chastity device without knowing what it was. And that is how she controlled how he used his dick.