A certain level of fearlessness and vulnerability is inherent to good erotic literature. Writing erotic stories is a sort of nakedness of the mind. Anyone can be caught scantily clad, their body laid bare. A gust of wind or an untimely rip of the pants can unveil a secret love of black lace panties. The physical world is so often out of our control. What can not be so easily exposed is eroticism hidden behind one's eye. You can't look at someone's naked body and know all it takes is the words "Good Girl" to render them immobile. There is beauty to the human body, yes. But beautiful too is the chilling warmth that runs down the spine as lips pressed gently against an ear say, "I want to hear you beg for it." People are turned on by thinking about how their secret desires might be taking place this moment, perhaps even just barely out of reach. They want to know that, on some level, the thing they want more than anything could happen. They want to indulge themselves in the fantasy in a way that scratches that secret itch and leaves them thinking ".... maybe I really could..." A certain level of truth and realness is necessary for great erotic. Even in fantastical situations, there needs to be some level of humanity; some vestige of the human condition. Great smut isn't about thrusting meat sticks in sacred caves. Great smut has tension, tenderness, struggle, pain, softness. It needs nuance and self-awareness. Hopefully a little bit of comedy in there too. If two mythical space aliens are fucking in space, there needs to be something human there to ground the reader. Or maybe they just want alien meat sticks to be stuck in alien sacred caves, I don't know. I'm just a writer. Let me write you some porn.