There was a knock at the door. After putting his clothes back on, Jon said "Come in." The door opened and he saw Karyn.
Her gaze moved over to Sarah, still on Jon's bed and still naked. "Oh. Sorry, Jon. I didn't know Sarah was here."
In her mind, Sarah was screaming Help me, you fucking moron! He's making me do things against my will! You think that I'd have actually have sex with this loser?! But her screams were not heard. Instead, a giggle was forced out of Sarah's mouth.
"Maybe later we could hang out?" Karyn asked.
"Sure," Jon said.
Then Karyn left. Jon turned around and smiled slyly at Sarah. The completely submissive and air-headed Sarah smiled back.
And again the real Sarah screamed, unheard. She was a prisoner in her own body.