He thought he had imagined it the first time. That night two weeks ago seemed so hazy now, and the after-effects of his father's specialty curses had left him drained and a little sore, but surprisingly euphorically hazy, and Sirius felt certain that if his father had ever let his victims live long enough for them to tell him about this particularly enjoyable side effect to his favorite curse he might stop using it.
That hadn't mattered then though, because lying in that dark room he felt safe, guarded, and when he opened his eyes all turned to color so sharp it almost hurt to see but he looked anyway.
Like when you slice your hand open, and you know it would be only a moment to heal with the right spell, but you don't heal it. Instead you stare in fascination and wait, for the sting you know will surface when the blood starts to flow, and you can't hide the morbid grin that splits your face when you feel it.
It didn't sting anymore though, because all the sharp color had dulled to vague blurs, and he should have been afraid that this wouldn't go away, afraid he would be blind as Prongs now, but he couldn't be, because Prongs wasn't real here.
This was a different world, full of shadows and dark glares and even if it was all warm and hazy now it would be cold soon enough. This was the house were Sirius Black, former heir to the fortune Black family fortune had been born and tutored. It was the house where Bella had burned his Quiddich robes out of spite, and been applauded by Sirius' own father. This was a mausoleum full of desolation and misery, and no place for the foolhardy spirits of Mssrs. Moony, Wormtail, Padfoot, and Prongs.
At some point during his musings Sirius thought he saw one of the fuzzy colors move forward, but try as he might he couldn't make out what it was, until a small frightened voice whispered his name.
"Sirius", the boy called, and Sirius slowly turned his head to the side. As Regulus leaned closer the colors sharpened, making him gasp in pain, then dulled, so that he could almost make out the pale form of his brother. Actually it looked more like a pale oblong blob, but he knew who it was all the same.
Regulus was muttering, and Sirius strained to hear him, which hurt, but then there were knees against his thigh and a small shaking hand on his cheek, which was nice and oh so cold. Maybe he had a fever. He had been so caught up in contemplating the hand, that it took him a minute to register the breath on his face.
Short hot pants over his chin, which smelled like the caramel toffees Regulus, always stole from the drawing room. Then there were lips against his. The lips were soft and small, very much like the hand still resting on his cheek, and some distant part of his mind knew this was his brother who was kissing him, but the colors were fading to dark and he was really too sleepy to care.
Days had passed without a word from his brother, and Sirius had almost decided he had imagined the kiss in his euphoric haze, until now. Now he could see and hear fine and there was definitely a weight pushing the bed down behind him.
Then there was the small hand against his cheek, and one leg cautiously drifted over to lie on top of his. At first he found it almost amusing, the way Regulus slowly crept closer to him, and then he grew impatient. He was five seconds from telling his brother to go and let him sleep, when he felt those lips again, this time on the back of his neck.
Sirius gasped, as the small shaky hand drifted down from his cheek to stroke, first across his throat, then down to his chest. As the kisses grew bolder, moving from neck to jaw to collar, the hand continued downward. Sirius chuckled quietly when his brother gasped at the feel of his firm abdomen and the hair leading down from his navel.
The tiny fingers followed the trail down, and hesitated for only a moment before sliding his small hand inside the bottoms. Sirius felt his brother thrust against his hip and realized for the first time the Regulus had crawled in bed naked. He considered mocking his brother's weak uneven thrusts, but the thought quickly fled his mind as those cool child-like fingers closed around his shaft. He could tell Regulus hadn't done this before, probably not even to himself, because the grip was loose, and the stroke was unsure and so slow that Sirius felt sure he would never be able to cum from this.
But then the hand on his shoulder tightened, and the hand on his cock grabbed desperately for his hip, and the small hips moving against his backside gave one hard thrust, and his brother gave a quiet sob against his back as he shuddered and came.
Sirius knew his brother was too young for wet pleasure, but even so, there was something strangely erotic in the jerky movements against him. After Regulus' breath was under control Sirius felt the hand slide back over to his hard cock. One, two, three soft slow strokes and he was cumming. Regulus wiped his hand on Sirius' soiled pajama bottoms, and wrapped his leg back around his brother's waist. Sirius shifted to pull Regulus on top of him, and within minutes both boys were asleep, each curled tightly around the other.