Control (2014)

Skin and Alex have an arrangement. She does absolutely anything he asks, including cooking, cleaning, and, whenever Alex wishes it, bending over so he can cum in her. There's only one thing Skin won't do. Tell him she loves him. But he's determined. So, to throw him off-course, Skin enlists a girl from the neighborhood to become her slave-in-training, hoping that he will turn his attention to her instead. But when Alex discovers Skin's plan, he decides to test Skin's decoy, to see how much she can take. Skin realizes what's happening and tries to get the girl to go, before Alex truly hurts her. But the girl doesn't want to go. She likes it there. She wants to stay.