The first thing he thought as he breached him was, "I'm going to Hell."

Though most others would have let sensation overpower thoughts at a time like this, his thoughts rang clearly. It wasn't that sensation was being ignored. Quite the contrary. It was only that, though the pleasure of carefully sinking into the scorching silken tightness of a lover for the first time in almost two decades caused his breath to catch in his throat and his limbs to weaken to the point they barely held him, coherent thought never ceased in Remus Lupin. Not when he could help it. Not after so many years of surrendering it to the full moon. The slow moan sounding from the sweet, swollen mouth turned modestly into his pillow was not even enough to tempt Remus to abandon himself to the bestial. Lust does not necessarily have to be mindless, and few could appreciate this as Remus could. And so even as he sank that last inch, even as all power of intelligible speech escaped him and he gazed with glazed and hungry eyes down at the exquisite, delicate grimace on the boy's face, Remus' mind functioned perfectly. And it condemned him.

James would never have forgiven him for this. Ever. But then, if James were living this situation might never have come about. Sirius might quite possibly have killed him for this, or close enough to it. Though, if Padfoot hadn't been lost, the two would never have been forced into such intimate circumstances. Remus fully appreciated these things, and also that he was betraying the confidence Dumbledore had placed in him when he had appointed him the boy's guardian. Remus fully accepted all the possible implications of this willful and intentional blasphemy, and he reminded himself, with each slow thrust and the whimpers it elicited, of the potential price of this trespass.

Oh! but it was sweetly urged. By the roll of narrow hips drawing him deeper than he dared himself. By the tentative but wistful touch of fingertips on his face coaxing him forward to crush soft, waiting lips with his own and taste their shudder, drink in their gasp as his fingers gently curled around the boy's weeping prick.

And he was a boy to Remus, he realized. Never mind that he might have been deemed the contrary by others: a lawful and consenting adult. Compared to Remus, he was a boy. And as the man deliberately crushing this boy's last remaining innocence, Remus asked for forgiveness. Each careful stroke of his hand along the swollen length was an apology: To Harry, for allowing him to waste such a precious moment on an old and lonely man. To the absent friends he was betraying with the act, to anyone who would be disappointed or enraged by this union, to whatever higher power might be listening, Remus apologized...

...For being unrepentant.

And he was. There was no guilt in him. The excuses he had contrived earlier, that he only wanted to ensure that Harry's first was gentle and loving and everything it should be, had been abandoned before he had ever allowed himself to touch his ward. This was no selfless act. Neither was it the result of a moment of weakness. Remus knew exactly what his intentions were when he first slipped his hand warmly over Harry's, holding his breath to see how he would respond, almost fainting with relief when Harry turned his hand to twine their fingers together. He'd known exactly what he was doing when he had reached out tonight and run his hands languidly down Harry's smooth, bare arms and wrapped the youth in a fluid embrace, taking his breath away with a gentle kiss. And he knew exactly why.

By no means did he expect or even hope this sacrilege would go unpunished. But since he was incapable of true contrition, he would have to devise some other means of atonement. In exchange for having this beautiful young man writhing beneath him, gasping his name, Remus would forgo the taming elixir Severus was due to deliver any day now. And in the meantime he resolved to face, unflinchingly, the gutting torment of seeing those brilliant green eyes shine up at him with trust he knew he didn't deserve.

Not that this expiation would benefit Harry. It was for his own peace of mind. But then, Remus would be sure Harry never knew it was required, or why. Harry would take as much enjoyment from this as it was possible for him to grant. Remus would never sully its sanctity with confessions.

Harry would never be given any reason to suspect that Remus was not making love to him but to Lily's eyes and James' face and Sirius' stubborn passion. He'd never know Remus' attraction lay in that Harry was the perfect embodiment of all of them, all those who Remus had loved so well and been denied; who had loved each other but never Remus. Not in this way.

More than that, Harry was a pulsing, breathing memory of a time when Remus had last known happiness. Happiness that had been shattered in so many ways by Harry's own entrance into this world. Remus didn't blame Harry for his loss. Gods. Of course not. The thought made him shudder with guilt that he could conceive it. And Harry, so innocent and sweet, mistook the tremor to be one of pleasure and moaned again, cried out as Remus delivered his apology with renewed fervour, and spilled warm over Remus' fingers like a kind of absolution.

If only.

That hopeful thought was too much for Remus, and he condensed the names of so many ghosts into a single, shattering sob, unable and undaring to utter Harry's own name as he emptied deep inside of him.

Spent, he rested against Harry, sweaty and weak limbed, kissing at the salty beads on Harry's own neck, lost in the comfort of trembling arms sliding up to circle his back. Perhaps this sin was not so wicked as it seemed, if Harry enjoyed it as much as he appeared to have. Perhaps Remus could just consider this to be something beautiful they could share, something worthwhile regardless of motive. Remus allowed himself to be seduced by this thought, until Harry's voice, choked and soft in his ear, shattered his contentment.

"I love you."

Remus' eyes fell shut. He knew Harry might be waiting for a reply, but he couldn't speak. He only wrapped his arms tightly around Harry, clinging to the dead, and he wept as he kissed him, hoping to stop the words from coming again. Harry whimpered into his mouth-so, so sweet-and surrendered to tears of his own, which Remus promptly kissed away as tenderly as the sweat before; drinking them in like merited poison. And he knew, as he watched Harry sleep after, that he would take this sin again, but that a thousand full moons could never possibly absolve him.