Switch: an erotic short story

Amy's been part of the BDSM scene for many years, but her new boyfriend Mark is completely inexperienced. She takes him to a dungeon, and promises to show him what she enjoys.But to Mark's surprise, Amy decides she wants to play the slave, and invites her friend Miho to teach Mark how to be a good master. This is the first in a series about a couple exploring their sexual boundaries.