Mistress Sofi had an upcoming exam but this guy kept talking when she did not feel like so she asked him to do something else and he could not. She had to shut him up and she did it with her feet as she continued reading. When that did not prove to be very effective, she did it with her ass and that was effective and he learned not to ignore what she told him.
Goddess Kira did not have much to do and so she decided to test her slave's breath retention for fun. She did not care what he felt and she knew that he had to do whatever she asked him so she used her ass and her latex pants to facesit on him. He was scared of what she did that he peed his pants. In addition, the mistress farted on him.
Mistress Sofi knew that this guy was scared shitless of being facesat on and being choked. So she did those things to scare him and to make sure he came clean over what he knew. And the information was enough for her to use to make a decision on other members of staff and that is how they got all the info that they wanted to get out of them.