Bed Cage
The audio makes reference to this piece of BDSM Furniture: A lockable cage in the bedroom, often under the bed, for submissive playthings to sleep in.
It's the first of the month, and the rent is due, but you just don't have the income to keep up with all the rising costs of living at your current place. Fortunately for you, your wealthy roommates desires (and yours) allowed the two of you to come to a compromise, of sorts... An alternative contract, covering your costs with a full-time chastity arrangement, and a few extra special terms you hesitantly agreed upon. Tonight, it's finally come time for you to step up and fulfill the rest of those promised obligations to your bestie. Of course, I'm sure, deep down deep, you really, really want this... Don't you? My Latex Sissy Maid.