From your head to your toes (baby mine)
The logical part of Regulus knew he shouldn’t be doing this. He should just apologize for being an inconvenience, clean himself up, run away, and never show his face again. Maybe if he was lucky, his brother would keep this humiliating incident quiet. The bigger—or maybe littler—part of him just knew that he was wet, cold, uncomfortable, scared, and his brother was warm and safe. For the first time in a long time wasn’t alone and the last shreds of his self control vanished. All he wanted was to be tucked away from the world in these arms forever.
So he did the only thing he could think of and cried. He cried and cried until he could no longer summon any tears and settled for whining into Sirius’ neck. All the while, his brother just rocked him, comforted, and hummed to him. If he was any less upset, maybe he would have been embarrassed.
“Oh baby. It’s okay, I promise.” He petted his hair as the last of his tears died away. Shyly, he peeked out of his hiding place. Sirius wasn’t looking at him with pity or disgust. He just seemed concerned. “There he is!” He said in an enthusiastic voice. If it were anyone but him, it would have sounded sarcastic, but somehow he made it seem genuine.
“How are you feeling, Reg?” It felt like both his mouth and head were filled with cotton. His throat hurt, his head ached, he was cold and miserable. He tried to speak, but all that came out was a pitiful whine.
Sirius hummed sympathetically, “I can imagine. Won’t you feel so much better once you get cleaned up?” Regulus nodded quietly, not really wanting to leave the dark stairwell where no one could see him but not wanting to upset Sirius either. “I’m going to get up now. We’ll head to the room for Littles, hmm?”
“Not little,” he mumbled, hiding his face in his neck so his brother couldn’t see how red his face turned at the lie. “Reg…” He heard but then Sirius’ voice trailed off, getting up, easily picking him up as well. He turned his face away to avoid looking at the wet patch on the floor. Thankfully, they didn’t come across anyone as he carried him to the room specifically for littles in Hogwarts. Usually, it was fairly active but today it was blessedly empty. By the time he got there, he was almost fully asleep, worn out, even though he had gotten more sleep than usual. The moment he was laid down on a soft surface, he fell asleep once more.
Gently, Sirius stripped the sleeping little of his wet trousers, wincing at the nasty red rash that covered his thighs. Clearly, he’d been using drying charms too often. As quickly as possible, not wanting him to wake up, he maneuverered him into a pull-up and a set of pyjama's. Erring on the side of caution, he swaddled him and put him in a sleep sack. He laid Regulus down in one of the cribs, then turned off the lights.
It wasn’t even half an hour later that Aidan walked in, carrying his sleeping little, Kayla, on his shoulder. The girl’s brown curls bounced slightly with every step he took, though he was clearly trying to be gentle. He paused as he saw Sirius in the playroom, and his eyes widened as they moved to the crib beside him. Sirius lifted a finger to his lips in the universal sign of ‘quiet’, and Aidan nodded. He laid her on one of the toddler beds and tucked her in before carefully approaching Sirius. “What happened?” He whispered. Sirius explained the entire thing, and Aidan winced in sympathy. “Poor kid. What now?”
“Shit’s really hit the fan, hasn’t it. Well, first, he has to be checked over by Madam Pomfrey as soon as possible. Then, I’ve got to figure out how to keep him from going back to the family. I know the only thing that would override their authority would be an official Caregiver-Little bond so I’ll have to make that happen.”
Both of them paused as Regulus began to shift and whimper. Sirius felt like someone had dumped a bucket of ice-cold water on him as he realized he was having a night terror. He’d had his own fair share and knew how unpleasant they could be. Then Regulus opened his eyes and sleepily looked around the room. He caught sight of Sirius. His eyes widened, he opened his mouth, and he wailed.
Unlike most nightmares that Regulus had, which had a distinctly phantasmagoric feel to them, this one was indistinguishable from reality. He could feel the cold stone of the Astronomy Tower under his knees, contrasting with the heat of the urine collecting below him in a puddle. The splashing echoed both in the narrow space and in his ears until he could hear nothing else. “Wow. I knew you were pathetic, but this is a new low even for you,” A familiar voice sneered. His breath caught as he looked up to see Sirius, his face twisted with disgust.
"Help! Please, Sirius!" He tried to say something, but all that came out was a low cry as Sirius’ face twisted further, and he took a step back to avoid the liquid that had begun to pour down the steps. “If even me, a Caregiver and your brother, can’t love you, then who can?”
No one.
Then Sirius turned around and left, leaving Regulus alone and helpless like always, tears spilling down his cheeks.
The transition from dream to reality was evident and slightly jarring. Suddenly, he was lying on a soft surface wrapped in something warm and dry. He opened his eyes to an unfamiliar room with a ceiling charmed to look like the night sky. Slowly, he looked around trying to figure out where he was. Then his eyes caught sight of a familiar pair of grey eyes, identical to his own. He began to struggle and realized the thing he was wrapped in was trapping him.
He screamed.