You need the ability to talk to Arlene in the Torture Rack, so at least the first part of Fawn's route needs to be done too.
I have done everything related to Fawn that I know of. I have long since finished her college segment, and we currently share a condo.
I'm not 100% sure on the exact requirements, but if Cassie, Fawn, and Alissa can all be taken on a date, the option to ask about her being a slave should be there.
Gotcha, I’ll re-check everything again. It’d probably be Alissa. Thanks.