With a wicked grin, Kelly activates the shock machine, sending pulsating currents through Mark's body. His cock twitches, growing harder with each jolt. She leans in, her tongue flicking against his hole, making him gasp. Kelly inserts the cock gage, stretching Mark's ass as she increases the machine's intensity. Mark's cries fill the room, a mix of pain and pleasure. Kelly's fingers join the gage, fucking him hard, as she laughs, "You're taking it so well, sissy." Mark, lost in sensation, can only moan in response.