From Inside The Grey House:
Vincent allowed her actions, as his nostrils filled with the smell of her blood. He enjoyed playing the submissive with her. It had always been the same between them. He could over power her, take what he wanted and leave her whimpering for more, but had no desire to do so. Since their first encounter, she held the dominant position. After nearly three hundred years, neither felt the need to change roles. The massive vampire allowed the diminutive woman to do as she pleased, as his wants and desires grew.
Cat Stark 