Slavery: A series of erotic games (book 04)
Everyone eventually, but not to start.
"Please pay attention, Whore, for what I'm about to tell you and show you is very important," I said. "You may not be a sex slave for longer than a week. It may not be for you as much as it is for me. To me, it's my focus, the fabric, the texture, the soul, of my life now. More than a mother, or a wife, or a businesswoman; I'm a sex slave. I don't expect you to understand it or need it as I do. I chose this life; you lost a card game. You're expected to serve a week then you may walk away, but you can't even be a pale imitation of a sex slave for your Master without enjoying everything about sex."