Slavery: A series of erotic games (book 01)
One did not disobey Mistress Dark.
"Not bad. She could be a little quicker, but we'll work on that."
Mistress Dark stuck two fingers into Lisa's cunt. "She's wet, but not too wet. I'll try to build up some of her slave heat." Mistress Dark came up to me and did the same, pushing two fingers into mine as well. "Not like this one," Mistress Dark said, "she's got enough heat for two." She pulled her fingers out, thick with my juices, and made me lick them clean.