In a sex positive worldview sex is always a good thing. Rape is not sex, it is a crime of power. There's a stark line between the two, which is consensual vs. nonconsensual.
I think it's really important to interrogate this idea - I've always felt slightly uneasy with the idea that "rape is about control not sex". Surely it can be both? Whether rape is an invading army raping women, a stranger jumping out on you from behind a bush or your husband forcing or coercing you, sexual behaviour (on the man's side) is involved. When we hear about men penetrating women in their sleep (often on MN threads) we understand that's rape. But isn't it also about the man seeing the women as his sexual possession who he should be able to use for gratification whenever he likes - yes it's about him having power over her, but it's also about him getting sex without what she wants mattering.
The history of marriage, and male-female power relationships (think slave owners and female slaves, male employers of female domestic servants, male movie or music moghuls and female would-be stars, and so on and on...) is about women being in situations where they have to provide men with sex because the men have the power - or face an alternative of losing their livelihood, home, children etc. For men as a class, sex and power have always been closely related.