Well sure, we can take it as a given that sex basically exists in its own special category. Biologically speaking, it's an impulse older than almost any other. I think that's self-evident enough without any need to tap into mysticism.

(Content warning: sexual violence in human history, abstract)

With that being said, it could also be argued that r-word is also deeply ingrained within human biology, particularly in the context of warfare. Even if we discount the (extensive) evidence within the anthropological record demonstrating this, there are clues baked into human physiology which seem to indicate that the human species itself is uniquely adapted to perpetrating r-word when compared amongst the other hominid species.

(Content warning concluded)

I apologize for bringing such a nasty subject up at all, but it's useful to weigh such things when talking about the deep biological roots of sex and how it makes us think/feel. I personally believe that it's too limiting to describe sex as an implicitly pure thing which only becomes wrong when certain impure people corrupt it. Please don't take that as a doomer statement! I personally see it as a triumpth that, through culture, we can collectively transform an act as ambiguous as sex into an idealized and pure expression of interpersonal love. I nevertheless do still try to be mindful of the capacity for sex to exist outside of the box we've crafted for it, though.