What do you do with jealousy?

Sirius tried to ignore it.

He tried to shove it down, like anger, like fear, like every other feeling he wouldn't let himself be controlled by.

He tried to tell himself it didn't matter.

But jealousy wasn't the kind of thing you could outrun. It had sunk its teeth in and refused to let go. Every time he saw Regulus and Snape together, it crawled out from where he'd buried it, wrapped around his ribs, and squeezed, whispering in his ear: That should be you.

And he hated it. Merlin, how he hated it.

Because what the hell did he have to be jealous of?

It wasn't like he wanted—

No. No, he wasn't even going there.

It wasn't like that.

Except—

Except he didn't want Regulus and Snape to get along.

He didn't want them sitting together, speaking in low voices, looking like they understood each other.

It shouldn't be Regulus.

It should be—

It should have been—

He was supposed to be the one who understood Snape best. They were supposed to know each other better than anyone. They shared this strange, sharp bond in a world that otherwise left them absolutely alone.

He didn't want Snape, who had become the most unexpected constant in his life, to shift his focus onto someone else.

And the worst part?

There was nothing he could do about it. Nothing he should do about it.

Because he had no claim, no right, no reason to be anything but grateful that Snape even acknowledged his existence. They weren't even friends.

Because Regulus was his brother.

And Snape—

Snape was just—

Snape was—

Sirius let out a sharp breath and raked a hand through his hair, pacing tight circles around the dormitory like a caged animal.

He needed to stop thinking about this. He needed to stop feeling like this.

So he did the only thing he could think of.

He grabbed a scrap of parchment, scrawled out a message, and waited for the owl to show up and carry his thoughts away.


Severus got the letter at breakfast the next morning and sighed before he even opened it.

Sirius Black was nothing if not persistent.

Inside, in Black's messy handwriting, was a single sentence:

.

ㅤㅤ So, you and my brother are best friends now?

.

Severus stared at it for a long moment. It was, somehow, not at all what he had expected. Trust Sirius Black to badger him endlessly, and still find new things to interrogate him about.

Then, with deliberate care, he flipped the parchment over, pulled out his quill, and wrote a response:

.

ㅤㅤ What difference does it make to you?

.

And then, because Black deserved it, he added:

.

ㅤㅤJealous?

.

Severus folded the note back up and, when the owl landed on the table again, tied it to its leg with a smirk.

This, he thought, would be fun.


Sirius stared at the note.

Jealous?

He hated how right Snape was. Of course, he was jealous, but not of what Snape thought.

Not of Snape spending time with Regulus, not of their stupid conversations in the library, not of the trust and affection that Regulus gave so easily, not of whatever strange camaraderie they had built while Sirius hadn't been paying attention.

No, Sirius was jealous of Regulus.

Because Regulus got to be close to Snape in a way Sirius never would.

Regulus could sit beside him without history weighing between them. He could talk to him without half a decade of rivalry and hatred making every conversation a battle.

Regulus got effortless familiarity.

And Sirius—Sirius got sharp words, careful distance, and letters that made his heart race for reasons he refused to name.

He hated himself for it.

Hated that Snape's words had sent something hot and uncomfortable crawling under his skin.

He couldn't afford to let himself act on it. Not anymore. He was determined to keep his emotions in check. But that didn't make it any easier.

And if Snape ever found out the real reason behind his jealousy, he would never let Sirius hear the end of it.

So he swallowed it down, pushed it deep, deep, deep inside, and picked up his quill.

.

ㅤㅤYou wish.

.

And because he couldn't help himself, because it was Snape, and Sirius always had to push just a little further, he wanted to add:

.

ㅤㅤYou must be loving this.

.

He wanted to send the letter before he could change his mind. But it wasn't the owl who appeared at his shoulder…

"Are you passing notes with Sniv—Snape now?"

James's voice was light, teasing, almost a joke.

But Sirius froze.

And James noticed.

"I really hope you wrote a good insult in there," James continued, smirking. "Or hexed the parchment to explode in his face…"

"You know I don't do that anymore," Sirius cut in, sharp and fast. Too sharp. Too fast.

The smirk slipped from James's face.

The air shifted.

Sirius could feel Remus still beside him, hear Peter pause mid-bite, sense the weight of James's confusion pressing in.

And then Lily, who had been watching from across the table, spoke.

"Well, that would be an improvement," she said lightly, stirring her tea. "Half his books from last year were in pieces. You know some of us do want to study for O.W.L.s."

James's jaw tensed. "Oh, come on, Evans, don't tell me you're choosing Snape's side again."

"I'm not choosing sides," Lily said. "I'm just saying if Sirius were writing to him, at least it wouldn't be to curse him this time." She shot Sirius a pointed look. "Right?"

Sirius swallowed.

He didn't want to lie.

Didn't want to explain, either.

So he forced a grin, shoving the note into his pocket like it meant nothing. "Relax, Prongs. Just settling some old debts."

James's frown deepened. "What's that supposed to mean?"

Sirius hesitated.

And Remus, ever perceptive, cut in smoothly. "It's not a big deal. Sirius has been… re-evaluating his life. You know, what to do if he really wants to stay as far away from his family as possible after graduation. The professors are getting to him, O.W.L.s, life choices and all that."

Sirius shot him a sharp look, but Remus ignored it, turning a page in his book like this was a completely normal conversation.

James did not look convinced.

"Re-evaluating?" he repeated.

"Like deciding who he wants to be, which turns out to be: not-a-complete-arse," Remus said. "Baby steps."

James let out a laugh, relaxing—just a bit. "Yeah, right. Sirius Black, not-a-complete-arse."

Peter followed immediately "Yeah, that'll be the day."

But Lily was still watching Sirius, scrutinizing him.

And she didn't look fooled.

Not at all.

Sirius exhaled slowly, turning his attention back to his plate, pretending that he wasn't waiting, hoping, for a chance to send the note to Snape.


James didn't press the note thing further.

Not exactly.

But as they were leaving breakfast, walking toward the courtyard, James nudged Sirius with his elbow and said, "Since when are you and Evans friends? She just called you Sirius, and not in the tone she usually uses when scolding us."

There was no teasing edge in his voice, just genuine curiosity.

Sirius blinked, caught off guard. "We're not," he said automatically. "We just… talk sometimes."

James squinted at him, like he wasn't sure if he believed that.

Sirius hesitated, then, because he had to say something to distract James, he added, "Maybe she'd change her mind about you if you stopped being so hostile to her best friend too."

James scoffed. "Oh, please, she's been mad at me since first year. You really think not hexing Snivellus is gonna change that?"

Sirius shrugged, playing it off. "Can't hurt. You know, maybe you could start by dropping that nickname."

James frowned, thoughtful.

And Sirius told himself he wasn't lying.

Not really.

Because Lily and him were talking because of Snape. Because of No One.

He was just bending the truth a little.

That wasn't so bad.

Right?


James didn't bring it up again.

But Sirius caught his hesitation when they passed Snape in the hallway. He saw the way James's hand twitched toward his wand, then curled into a fist instead.

He noticed James glance at Lily afterward, like he was waiting for her to notice, for some praise or validation.

She didn't.

Or if she did, she didn't give him the satisfaction.

Sirius smirked to himself. Baby steps.


That night, after everyone else had gone to bed, Sirius pulled out Snape's last note.

Jealous?

He exhaled, running a hand through his hair.

He couldn't tell Snape what he was really jealous of. Couldn't tell him what exactly had been gnawing at him since he had seen Snape and Regulus talking so easily.

But he also didn't want to leave things unanswered.

So he grabbed a quill, hesitated, then finished what he had started:

.

ㅤㅤYou'd love that, wouldn't you?

.

But it read too much like Sirius Black to Severus Snape, so after a long pause, he added:

.

ㅤㅤ Maybe I just don't like being left out.

.

Which was true.

Sort of.

Maybe.

He folded the parchment, tied it to the owl's leg, and sent it off before he could regret it.

Then, he sat back on his bed, staring at the ceiling, waiting to see if Snape would answer.


Sirius didn't expect a reply.

But the next morning, as he sat at the Gryffindor table, an owl dropped a folded scrap of parchment in front of him.

He opened it.

.

ㅤㅤ If you don't want to be left out, you could always sit with us at breakfast.

.

And below that, in smaller writing:

.

ㅤㅤ Unless, of course, you're all talk.

.

Sirius's pulse kicked up.

It was a challenge.

Snape expected him to back down, expected him to never risk his precious reputation by sitting with Slytherins.

Sirius smirked. Fine.

If Snape wanted to play, he'd play.

He stood, grabbed his plate, and walked—calmly, deliberately—toward the Slytherin table.

Conversations quieted as he approached.

Regulus looked up first, brows pulling together in confusion. "What are you—?"

But Sirius didn't answer. He just dropped onto the bench beside Snape, across from Regulus, and started buttering his toast like nothing was unusual.

Silence stretched.

Someone further down the table muttered, "What the hell?"

Snape, to his credit, didn't react. He just sipped his tea, unimpressed. "Didn't think you had it in you."

"Please," Sirius said, biting into his toast. "I don't scare easily."

Regulus looked between them, eyes narrowing. "What is this?"

"A social experiment," Snape said dryly.

Sirius grinned. "I think it's going well."

Regulus looked like he wanted to argue. Or maybe just shove Sirius off the bench.

But Sirius saw the flicker of something in his eyes—something almost like reluctant acceptance.

And for the first time in years, Sirius sat with his brother at breakfast.

.

Sirius knew Regulus wasn't going to let this slide.

He could feel his brother's gaze burning into him, waiting, calculating.

And sure enough, Regulus's challenge came, direct and sharp, just as Sirius had expected.

"What are you really doing?" Regulus finally demanded, his voice low and measured.

Sirius took another bite of toast, as if he wasn't feeling increasingly cornered. "Eating breakfast."

Regulus didn't look amused. "At the Slytherin table?"

Snape made a quiet sound, something that could almost be mistaken for a laugh, though his face remained impassive. Sirius ignored him.

"Didn't realize that was illegal," Sirius said, flashing his most insufferable grin. "Or is there a rule I don't know about?"

Regulus rolled his eyes. "You know what I mean. You've spent the last five years acting like we're the plague, and now suddenly you're one of us?"

Sirius tensed, despite himself. "That's not what this is."

"Then what is it?"

Sirius hesitated.

He could say the truth, something about Snape, about their letters, about No One, but that wasn't what Regulus really wanted to know.

So instead, he shrugged, leaning back. "Thought I'd see what all the fuss was about. The greatest house of them all, or so I've been told."

Regulus narrowed his eyes, clearly unconvinced. "So this isn't another pathetic attempt at making amends?"

Sirius's stomach twisted.

He forced a laugh. "Oh, please."

Regulus tilted his head, studying him, the way he always did when they were younger—like he could see straight through Sirius's defenses, like he was searching for the lie.

Sirius stared back, refusing to flinch.

Snape, for his part, just sipped his tea, clearly enjoying the tension.

Finally, Regulus exhaled, shaking his head. "You're an idiot," but even that carried a hint of something softer.

"And yet, your favorite idiot." Sirius grinned, responding automatically like old times, as if nothing had ever come between them.

Regulus muttered something under his breath and turned back to his plate, clearly done with the conversation.

But Sirius noticed it—just the faintest twitch at the corner of Regulus's lips, almost imperceptible.

As he sat there, an unexpected lightness settled in. Years of silence, of distance, seemed to ease, even if only a little.

This wasn't how he imagined they'd reconnect, but then again, he would never have imagined himself sitting at the Slytherin table, either.

He looked around, the absurdity of the situation hitting him once more. Everything felt out of place, but in an odd way, it didn't feel entirely wrong—not something worth spending half his life, and his relationship with Regulus, fighting against.

Maybe the Slytherins table did serve a better breakfast. For this was the best he'd had in years.


Notes:

Since this is a no-war AU, I think it's just normal school rivalries between the houses, not the whole two sides of the war thing. Of course Severus hasn't forgiven Sirius, not completely, nor does he consider him a friend, but Sirius is making progress. At least, at this point, he isn't a walking trigger for Severus yet. And sitting at the Slytherin table is a huge gesture coming from Sirius. It's significant for both Slytherins, but especially for Regulus. After all, Sirius choosing Gryffindor was how their relationship first fractured.