We’ve done ourselves a great disservice in our understanding of sex.  While it is true that sex is driven by an evolutionary impulse to reproduce, that is only one facet of our drive for it.  Truly, sex is closer in nature to art than any ‘primal instinct’ humans experiences.  Both are fueled by expression and catharsis—release of passion(be it anger, lust, love, hate, etc). Just as art is fueled by a desire to leave your mark on the world (however subconscious that desire may be), sex is as well.  And both are meant to express and illicit an emotional or physical reaction between two parties. Artist:Audience::Lover:Lover. In our debasing of sex into an act of reproduction, we have enabled bigotry and hate (those who aren’t or are unable to be reproducing are sluts, queers, freaks, etc).  And just as with art, sex without purpose (lack of that passion for expression) feels hollow.  Sex without purpose is a manufactured pop-song, but that is not to say that sex for a different purpose than reproduction is immoral—just singing a different tune.