OUCH! These gals are all merciless. That flatmate obviously has a taste for and understanding of how to humiliate her chastity boy. Good for her.
The combination of chastity keyholder versus girlfriend fascinates me. There's interesting material in when they are not one and the same. Flatmates fascinate me too ... they are usually close enough for there to be some sexual interplay, without there necessarily being a relationship. Good source material there ... but maybe I am just dreaming about my own flatmate of years gone by. :-)