It sometimes lingered a few days after the moon began waning. The skinny brown-haired boy with the wide mouth and the slender fingers still held the shadow or echo of the wolf, unstoppable, uncontrollable.
Sirius gave into that, freefell into it, raised his spine off Remus' bed and twisted raptured fingers in his pillows, his body glowing black and white in the moonlight.
He might have been a ghost, sliding across the darkened dormitory. A shock goes through Remus' body as the sound approaches – the slap of a boy's bare feet on hard wood floors – and stops at the side of his bed. He keeps his eyes closed as Sirius' hand wanders over his cheek, pushing his face to the side, and wakes only when his lover's fingers trail over his mouth, and he turns and bites them, baring his teeth, resting his eyes on Sirius', laughing silently.
Remus tastes the leather and metal, the musky flavour mixing with the sharp coolness against his tongue. Sirius wriggles against him, his neck arching where Remus suckles the collar, his hips squirming forward to meet Remus'.
Sirius is moaning almost helplessly, and his hand is tangling in Remus' hair, his other arm thrown back against the wall, until Remus slides one slim, delicate finger under the collar, and growls, "lie down. Stay."
When Sirius sleeps, Remus watches his purple-white eyelids flicker in the moonlight, watches them move with his dreaming.
Sirius' chest is bare and smooth, and Remus leans his forehead against it, kissing the warm flesh, flickering tongue and teeth over the dark nipple, dreaming cities of his own imagining.