He will be a different sort of person than his victim. His desire to use, hurt, overpower, or destroy will be authentic and dangerous. There will be a real possibility that things could get out of hand. There are a lot more people having rough sex than there are individuals taking on the stigmatized identities that comprise the leather family's taxonomy. These experiences are not carefully thought out or planned.
Consent is expressed by the failure of the bottom to escape.
The victim's refusal to scream his head off is the equivalent of a safe word. Rough sex is clandestine, rushed, made more thrilling by the fear of detection. Any pain is provided by the simple expedient of a blow or a bite. Because it has no pretensions of being healthy or politically correct, rough sex can proceed in a more fluid fashion, without the yawnsome interruptions for polemics that pepper the Marquis de Sade's and John Norman's works. It is the first pen to contain the herd and serves to divide the completely clueless from those who might have some spark of potential.