Warnings: this story contains mentions of male/male sex, so if that's not your thing, read something else.
D suspected that something had been overlooked when, in order to prevent themselves from dwindling to extinction, his race chose their solitary path.
It was not just himself he was thinking of. His father had hated humans more than anyone, was willing to wipe the entire species from existence, yet there had been something about the way he reacted to Vesca Howell. The federal agent had followed him for years, obsessively tracking him from one place to another, but his father never made any attempt to put a permanent end to the pursuit. And his grandfather, despite being the one who had taught D his purpose, had once had a relationship with someone who, if not exactly human, had been close enough. D had seen the photograph to prove it.
D knew his duty, and although he lingered in Los Angeles long past the point where his association with the detective could be considered a casual acquaintance, in the end he made himself leave. When the detective appeared on the ship, he pushed him away, over the edge and back to the human world where he belonged. The detective never should have been there in the first place and there was no reason for him to have any regrets for his actions.
But he couldn't help but marvel at the way his hands felt afterwards, the palms and fingers that had rested oh-so-briefly against Leon's chest tingling with a sensitivity close to pain, like the lingering throb after a mild burn.
That was what relations between his own kind and humans reminded him of: the way a moth was drawn to a flame. An instinctive flirtation with danger that they could not resist, despite the consequences. A moth was drawn to the brilliant light at the heart of a fire, even as the heat warned it away. Dancing around it, drawing nearer only to pull away again, until either the flame died or the moth ventured too close and perished from sudden immolation.
Neither possibility sounded appealing, so D did his best to keep his distance.
There was plenty of heat to warn him away when Leon finally caught up with him once again, yelling and cursing and angry accusations that reminded him just how graceless the detective could be, how wilfully blind in the pursuit of his own purposes, but despite this, D couldn't help himself. The look of surprised confusion on the detective's face as D stepped towards him was amusing, but it was a fleeting thought before he received confirmation of what he'd both dreaded and anticipated all along.
He was not surprised to go up in flames, the edges of himself melting away. It was inevitable, after all, when one ventured to close to fire, and Leon was definitely that. And although D knew better than to fight fate, he could not surrender gracefully to it, either, not this time. Instead he pressed closer because it was not yet enough, even with Leon inside him, pushing deep and spreading him wide until every part of himself was lost to the blaze that consumed them both. He was surprised to discover that being burned alive didn't hurt, the exception being the desperate need that twisted inside him to the point of pain. Then came the final immolation as the world disappeared in a flare of white-heat and sensation, too much for him to endure.
Afterwards, he knew that he had survived against all expectations by the pounding of his own heart echoing loudly in his ears. He was lying on one of the couches, the detective sprawled on top of him. And Leon, too, was alive, judging by the panting breaths against the flesh of his neck. His clothing was gone, and D had little hope for finding it in one piece, but he was reasonably sure he could feel the denim of Leon's jeans still wrapped around one ankle.
D blinked mismatched eyes up at the ceiling and wondered just how he could possibly have enjoyed anything so crass and undignified as this, along with why he didn't do it sooner.
It wasn't until Leon began to move that he noticed one of his hands dangled over the edge of the couch, that fingers intertwined securely with his own. They squeezed gently, a gesture that held an odd sense of promise, and D sighed, content even as the detective pulled away, an embarrassed and uncomfortable look on his face.
Perhaps D's fascination with the human detective promised his eventual destruction, but least he knew he wouldn't burn alone.