Disclaimer - I don't own Harry Potter. This is written for Froday amnesty for April 2022 for prompt 11.20, the prompt being "age" for which I choose mental age repression rather than a physical age regression which resulted in a sequel to another one-shot I've written.
Indignity of Padfoot
Sirius glared at the prisoner, his mood far from delightful as he did so.
"And why am I doing this again instead of being out on Order business?"
The man who was supposed to be his best friend replied by saying, "Sirius, watching your little brother is Order business."
Sirius continued glaring at the figure now perched on one of Lily's kitchen chairs, leaning forward into the table while staring out the kitchen window as Sirius sat in another one of the chairs, his arms, and chin perched on the back as he felt like seriously lashing out at someone, Regulus in particular. He ignored the sigh that came from James' girlfriend, who Sirius considered the biggest traitor ever.
"I'm going to head out for a bit."
"So you're saddling us with the prisoner?" Sirius asked.
"Sirius, your brother, is a guest under our protection, not a prisoner," Lily corrected. "Dumbledore and Moody have both said as much. But you should be grateful Regulus is even alive." There came another sigh. "So—while I'm gone, keep an eye on those bandages and that he doesn't move in a manner that opens up his injuries, particularly the ones on his pack, hip, and left arm."
"It's not as if he's going to be moving about without us moving him, now is he?" Sirius snapped, looking at the wall so he didn't have to see Regulus in that state, the state of having mentally regressed to that of a small child, to the point he was as complacent as a newborn babe—and also wearing diapers of all things, not to mention having to be fed like one. "And you didn't answer my question, traitor."
Lily grabbed his chin, not caring that he gave her the most murderous glare he could muster as he continued pouting. "You're acting like more of a child than he is," Lily said. "Though I can't blame you, given you can't possibly like seeing Regulus like this. As for a reason I'm abandoning you and James to Regulus babysitting duties," Lily glanced over at Regulus, "I'm going out shopping. For him."
"Would you rather be doing that?" James said, letting out a sigh. "And she's right about you acting like a child."
"I don't want anything to do with him," Sirius muttered, knowing that he was lying in the back of his head. "Both of you know that."
"Uh-huh," Lily said, clicking her tongue. And then she was off, leaving them with the Death Eater, who was oblivious to everything around him.
Or so Sirius thought.
Regulus' mouth started moving, still looking out the window, and Sirius thought nothing of it beyond the fact his brother might finally be able to talk to them, what with Dumbledore not even wanting to try Legilimency on the boy lest he breaks even further, which would, in turn, mean he wouldn't be stuck with the brat. But then Regulus started to try and blow, the air coming out of his mouth, and Sirius sat up straighter, beginning to get worried. "Reg?"
Whistle.
A damn whistle came out of his brother's mouth.
Then another, as if he were—
Sirius stared, horrified as Regulus sat there leaning against the kitchen table, whistling bird sounds at a bird outside the window. Still, there was a faint smile on Regulus' face and a twinkle in his eyes that said he was actually enjoying himself even though Sirius definitely was not. Then, much to his horror, Regulus lowered his arms and leaned back in the chair, the first voluntary movement they'd seen from him since he'd arrived at Lily's place a few days ago.
And much to Sirius' horror, Regulus began flapping his hands at his side, up and down as if they were bird wings, stopping every so often. He'd tilt his head so he could watch better, and the whistling increased in frequency.
"Reg…" Sirius sucked in his breath. "Hey, Reg."
And as his panic set in, James walked over, smiling softly and acting as if it were completely normal to treat his seventeen-year-old brother as if he were a toddler instead. "Do you like birds, Reggie?"
Regulus didn't respond and simply continued the activity that preoccupied him, and James watched, still smiling yet looking sad, meaning that what was going on wasn't affecting him. But then his eyes widened, and a big grin on his face appeared. "I know!"
Sirius stiffened, shaking his head. "I don't like that look on your face, matey."
"Padfoot," James said in a rather sing-song voice.
"Matey, no. Please." Sirius shook his head more vehemently. "I really don't like that look on your face."
"We need Padfoot," James said.
"What?" Sirius pointed himself. "I'm here already."
"No, the other Padfoot. And he's not paying attention, so…"
"No."
"Just do it, or I'll turn into Prongs instead. In Lily's kitchen where I might break something," James said, grinning ear from ear during a situation he shouldn't be taken so lightly.
Yet, Sirius did not want to get in trouble with Lily, particularly after spending a lot of time and effort taking care of Regulus when she didn't have to, something he had to admit begrudgingly. And she'd saved him, pulling him off the street as she had. He let out a sigh, standing up from the chair and transforming. He sat down on the floor with a plop before looking up at James in disgust, not liking the look of mischief on James' face.
James turned to Regulus and said, "Hey Regulus." Not that Regulus responded. "Do you like dogs?" Dog Sirius glared at James, not liking where it was going as Regulus continued to do his own thing, the bird sounds and flapping of hands at his side continuing as if he were utterly oblivious to what James was saying. "We've got a dog here."
Regulus stooped, flapping, stopped whistling, the smile on his face leaving as he turned to look at James. His mouth opened, and he said, "Poop?"
"What the Bloody Merlin!" Sirius thought to himself as James started laughing, one finger pointing at Sirius, so Regulus was now turning his head to look at him. "The first word we get from him is poop?"
Regulus now stared at him, taking in fact there was indeed a dog there, but then—
A sudden feeling of dread rushed over Sirius as a rather large grin broke out across Regulus' face. "Poop!" he said again, with a level of enthusiasm no adult in their right mind would have for the word poop. And then Regulus said, "Poop! Poop!" Due to Sirius' dismay at the word poop coming out of the mouth of his always proper younger brother, he didn't notice Regulus leaning forward until the young wizard literally lunged at him, his arms wrapping around his neck as he cried out, "Poop! Poop! Poop!"
The gut reaction to Regulus launching at him saying poop very loudly was to shift back, resulting in Regulus knocking him over backward as Regulus repeated poop, and James was laughing even louder at his personal predicament. And as he fell back, one hand reached up and around to Regulus' back in an attempt to support his younger brother, who was now falling with him.
"Poop!" Regulus said, touching his face to his brother's chest as he also attempted to hug Sirius. But then, Regulus tensed and stopped saying the word poop for some reason. Sirius opened his eyes, feeling his brother shift, seeing him frown in confusion.
"Um. Reg. What's the matter?" Sirius asked, only to find Regulus shifting himself upward slightly, wobbling as he loomed over Sirius, frowning as he did so, his face only mere inches from Sirius' own face. "James, a little…"
The gray eyes suddenly widened, the look of confusion on Regulus' face softening to one of recognition, and his mouth opened. "Fre-fre?"
"Fre-fre?" James said as Sirius choked back his own recognition.
"Fre-fre!" Regulus said excitedly. And then—
Regulus let himself collapse onto Sirius, not noticing how Sirius' own body tensed as Regulus started to nuzzle his face into his brother's neck, Sirius' shirt clenched tightly in his fists as he did so. "Fre-fre!"
"Okay. I get that poop was his attempt to say puppy, but what is this fre-fre?"
Sirius took a deep breath, trying to hold back the tears that were threatening to come out as his arms wrapped around Regulus' back as his brother continued to snuggle into him as if he were the embodiment of safety at that moment. He choked slightly, letting his own fingers twist into the back of the shirt he was lending Regulus, one that was too big for his small frame. "Fre-fre."
"Sirius. You," James was no longer laughing. "You look like you're ready to cry? What…"
"Fre," Sirius swallowed. "Is short for frère."
"And that means?" James asked as Regulus continued calling out fre-fre as he snuggled his older brother.
"Brother," Sirius said. "Fre-fre is…" He couldn't say that it was a long-lost nickname from their childhood that their mother had decided to stamp out because no proper Pureblood spoke in baby talk towards their elders and their betters despite the fact Sirius adored when Regulus would call him that. He could feel the tears welling as he held onto Regulus, but then—
He felt through the clothes Regulus had borrowed as there was none of his own to be had the adult diaper Regulus was now wearing because of his impaired mental state and—
He was crying.
And—
"Fre-fre?"
It was soft, that tone of voice Regulus used before—
And then Regulus was crying, sobbing into Sirius' neck and crying hard. And at first, Sirius couldn't stop crying himself. "Reg. Dear one. What's the matter? Why are you crying?"
"Sirius," James said, his voice serious. "Regulus is crying because you're crying."
Sirius sucked in his breath, closing his eyes, forcing himself to calm himself, not moving into a sitting position even though he wanted to hold Regulus that way simply because he knew what kind of condition Regulus' back was in. He started whispering words of comfort to the young wizard, urging him to stop crying.
Suddenly, the crying stopped.
"Oh, good Reg, you…" Sirius paused, looking at his younger brother carefully.
A soft snore came from Regulus.
"Sirius, I don't think you'll be moving from that spot any time soon."
"What do you mean I'm not?"
"You know that Regulus has been fighting us to go to sleep, and he wakes up crying when he sleeps. Meaning he's having nightmares."
"Oh, great," Sirius said. Yet he got it. "Next time, let's find a more comfortable spot for the two of us when he needs a nap?"
"Come on. It's absolutely adorable."
"Regulus isn't three, you know."
"It's still adorable, and you can kind of pretend that he's not, you know, in the mental state he's in right now because all he's doing is sleeping peacefully."
"Yeah, he's…" Sirius paused, staring. Somehow the tip of Regulus' finger had gone up to his mouth. He let out a sigh. "Hopefully, he's awake before Lily gets back."
Regulus wasn't.
Lily came in, frowning, placing her shopping bags onto the table. "What happened here? Not that I'm complaining as this is a good development, given how things have been the last few days."
"Regulus played with the poop."
"James! Not funny!" Sirius said, feeling Regulus start to stir awake, which was good as his body had begun to stiffen from being stuck in his position. Not to mention his mind was bored.
"He's right. Not funny, James."
"But Regulus really liked the poop."
"I don't want to hear about Regulus playing with his poop, but if the two of you practiced more common sense when changing his diaper…"
"We've not changed his diaper," James said.
"Poop is puppy!" Sirius said. "As in my Animagus form!"
To which Regulus stirred away, lifting himself slightly, frowning as his face was yet again inches from his face. And then, "Fre-fre!"
There Regulus was nuzzling his face again. Lily frowned. "Fre-fre?"
"Sirius says fre is short for frère."
"French for brother," Lily said. "Want some help sitting up, Sirius, so you don't disturb Regulus. We can also help you move to a spot where your back is better supported."
"Please!" Sirius said. "And he can't cling to me all day! We can't keep doing this."
To which the answer he got was them helping him get over to the couch, though not into it, so his back was supported as Regulus continued snuggling into him.
Lily walked over to her packages, pulling out something she hid behind her back. She came over and got down onto the ground without revealing it. "Hey. Regulus. I've got a gift for you."
To which Regulus stopped moving and stared, still clinging to his brother, smiling the entire time. Sirius was also curious regarding what Lily had.
And then—
Out came the teddy bear.
"Eee!" Regulus said, reaching for the teddy and snatching it away, hugging it to himself as he started to sit next to Sirius instead of on him, gently nuzzling the teddy's face into his neck as he leaned in, rocking the creature gently in his arms.
"Huh," James said. "That's adorable. He's just like a little kid."
"That's what I've been thinking, that Regulus has regressed mentally to a younger age," Lily said finger on chin. "How about a kitten?"
"What?" Sirius stared.
"Um, Lily…"
"He could play with it and snuggle it. It would mean he wasn't clinging to Sirius twenty-four-seven either, because even though Sirius is obviously enjoying the affection, Regulus is lavishing on him right now…"
"Am not!" Sirius muttered.
"You are, but you're not going to be able to keep it up without getting overwhelmed, and that runs the risk of you getting snippy with your brother."
"Oh. Sirius cried while you were gone."
"Not cool, mate!"
"I'm bringing it up because the moment you started crying, which was because you are upset at what's going on with him just like we are, though more so as he's your little brother," James said. "I bring it up because the moment Sirius started crying, Regulus started crying."
"Oh, dear. Yeah. The next thing to get is a kitten. Just, trust me on this one because I do think Regulus understands what's going on around him, even though there are some things he's not aware of. And, no talk about anything related to what's going on in the world right now around him."
"Yeah, I think that's best."
Sirius sighed. "I'm going to trust your judgment on this, you guys."
