UTC Andrea, Yes, I know that rape is often committed with objects.
Rape is an act of power.
But if we try to ignore its frankly sexual nature, we not only close our eyes to all the evidence that stares us in the face, but we deny the frequently sexual nature of power itself, and the way sex and power are intimately intertwined. I'd say this was true for women as well as for men, though in different ways. Sex and sexual arousal don't exist in a vacuum. It can well be that when two people are having sex, in the man's mind he's engaging in an act of power, of conquest, even domination, which to him in this context is sexualized. Power in that sense is erotic.