" The sensation wasn't repellent, though she had believed somewhere it would be. Someone had left her with that impression, but, whoever they were, they were wrong. It was ... mesmerizing. She could sense the length of him against her buttocks as well as a kind of heaviness, a substantive presence. He was changing right there under her, growing longer and thicker, information she acquired through the unlikely source of her bum, while he kissed her mouth. "

― Judith Ivory , The Proposition