Ashley and Sabrina started to change into their nighties, while Karen came over for a surreptitious word. She spoke in a whisper as she handed me a shopping bag, "Here, go into the bathroom, remove all your clothes and put this outfit on instead; and only this outfit: no underwear at all."

"What is it?" I asked nervously, also whispering.

"You'll see," she said with a devious smirk.

"Ok," I said.

"And once you come out, and I mean that both ways, for the rest of the night you will address the rest of us as your Mistresses, with all that implies," she demanded with authority.

"Understood, Mistress Karen," I...