It had started with a stupid argument, as most things involving Regulus Black-Rosier tended to.
“You’re insufferable, Rosier,” Severus said sharply, his patience worn thin. He was seated comfortably in one of the armchairs in the drawing room at Potter Manor, James perched on the armrest beside him, playing with Severus’s hair absentmindedly. James’ casual affection seemed to irritate Regulus even further.
“Aw, come on, Snape,” Regulus drawled lazily from across the room, sprawled out on the couch like he owned it. “Why so uptight? Is Potter distracting you too much to think properly?”
James shot him a mock glare but didn’t rise to the bait. “Leave me out of this, Reggie.”
“Not a chance, Potter,” Regulus shot back. “Honestly, I’m amazed you managed to get Snape to date you in the first place. I mean, no offense, but he doesn’t seem like someone who’d know what to do in a relationship, let alone in bed.”
Severus froze mid-sip of his tea.
James raised an eyebrow. “Reggie. Don’t.”
“What? Am I wrong?” Regulus asked with an innocent shrug. “I’m just saying, it’s hard to imagine someone as uptight as Snape being remotely fun in—”
“That’s enough,” Sirius interjected quickly, looking mildly alarmed. “Reggie, maybe don’t—”
But it was too late. Severus had already placed his teacup down with an almost exaggerated calmness. Slowly, he stood up, brushing imaginary dust off his robes, and fixed Regulus with a withering stare.
“Regulus,” he said, his voice deceptively calm, “do you ever stop to think before opening your mouth, or do you just say whatever idiocy floats to the surface of your tiny little brain?”
“Oi!” Regulus protested. “You don’t get to insult my brain just because you—”
“Oh, I’ll do more than insult it,” Severus cut in smoothly, a dangerous gleam in his eye. He stepped closer, his smirk growing more wicked by the second.
James, sensing danger, opened his mouth to intervene, but Severus shot him a look that effectively told him to sit down and shut up.
“Let me enlighten you, Rosier,” Severus said in a voice that sent shivers down everyone’s spines. “Since you’re so interested in my… capabilities.”
“Sev, maybe don’t—” James tried, but Severus ignored him.
“Did you know,” Severus began, tilting his head slightly, “that I used to sleep with your brother?”
The room went dead silent.
Sirius, who had been halfway through a sip of butterbeer, promptly choked and sprayed it all over the floor.
Regulus blinked, his face slack with disbelief. “You’re joking.”
“Oh, I assure you,” Severus said, his smirk widening, “I am not joking.”
“You—Sirius—you—” Regulus pointed a trembling finger between his brother and Severus, his voice faltering.
“Yeah, we did,” Sirius said suddenly, crossing his arms and smirking a little. “Got a problem with that?”
Regulus’s jaw dropped so far it was a wonder it didn’t hit the floor. “YOU’RE PROUD OF THIS?!”
“Why wouldn’t I be?” Sirius said with a shrug, clearly enjoying his brother’s meltdown. “Snape’s got a certain… je ne sais quoi. Have you seen him in those bloody tailored robes?”
“Do not talk about me like I’m not standing right here,” Severus snapped, though there was a faint hint of color in his cheeks.
“This cannot be happening,” Regulus muttered, putting his head in his hands. “My brother… and Snape… this explains so much.”
“Glad you’re finally catching up, Reggie,” Sirius said cheerfully.
“Sirius, stop encouraging him,” James said, rubbing his temples. “This is already out of control.”
“Oh, I’m the problem?” Sirius said with mock outrage. “Your boyfriend’s the one who just dropped the bombshell!”
“Speaking of which,” Severus cut in, his smirk returning, “shall I recount the details of the astronomy tower incident?”
“THE TOWER WAS OFF-LIMITS!” Sirius barked, looking both outraged and oddly nostalgic.
“I knew something was up with that curfew violation!” Remus exclaimed, smacking his knee.
“Oh, don’t forget the Prefects’ bathroom,” Severus added, ignoring the growing look of horror on Regulus’s face.
“NOT THE BATHROOM!” Regulus practically shrieked, standing up and pacing in frantic circles. “I don’t need these mental images!”
“Why not?” Sirius asked with a grin. “It’s character-building.”
“YOU ARE NOT HELPING!” Regulus shouted, looking like he was two seconds away from a full-on breakdown.
James pinched the bridge of his nose. “Sev, was this really necessary?”
“Absolutely,” Severus said simply. “He had it coming.”
“And you didn’t even tell me you and Sirius—” James started, his voice trailing off in a mix of disbelief and exasperation.
“Would you have wanted to know?” Severus asked coolly.
“…Probably not,” James admitted after a long pause.
“Exactly,” Severus said, turning on his heel and sweeping toward the door.
“Sev!” James called after Severus as the Slytherin turned on his heel and began to sweep toward the door. “You can’t just walk away after dropping that bombshell!”
“Watch me,” Severus replied, not even glancing back.
James groaned, muttering, “I’m going to marry that man, and he’s going to drive me insane.”
“Good luck with that, mate,” Sirius said, laughing.
Regulus, meanwhile, was muttering incoherently. “Sirius and Snape… the tower… the bathroom… I need therapy.”
“Oh, Reggie,” Sirius said cheerfully, ruffling his brother’s hair. “You’re so easy to wind up.”
“Don’t touch me!” Regulus yelped, swatting Sirius’s hand away. “I hate all of you.”
“Love you too, little brother,” Sirius said with a wink.
Back on the couch, Barty and Remus were in tears from laughing so hard.
“This is the best day of my life,” Barty wheezed.
“I’ll be processing this for years,” Remus added, wiping his eyes.
“Honestly, I think I handled that pretty well,” Sirius said, grinning.
“Handled it?” Regulus shrieked, looking up at him with wide, panicked eyes. “You just admitted to sleeping with Snape, and you’re acting like it’s a bloody joke!”
“Because it is,” Sirius said with a wink.
Regulus groaned and buried his face in a pillow, while Lily, Remus, and Barty dissolved into laughter once again.
---
Somewhere down the corridor, James finally caught up to Severus. His boyfriend was striding purposefully toward his study, his robes billowing behind him in their signature dramatic flair. James, still reeling from the chaos in the drawing room, grabbed Severus’s arm and spun him around.
“You’re evil,” James panted, his hazel eyes wide with a mix of disbelief and lingering panic.
“I’ve been told,” Severus replied coolly. “Why are you chasing me?”
“Why am I—” James sputtered, gesturing wildly toward the direction of the drawing room. “You just casually admitted to sleeping with Sirius Black. My Sirius Black. Well, not my Sirius, but you know what I mean—my best mate, Sirius Black. And then you just walked away like it was nothing!”
Severus tilted his head, studying James with mild amusement. “Would you rather I stayed and provided graphic details?”
“NO!” James yelped, his face flushing. “I mean—no. Definitely not.” He paused, running a hand through his perpetually messy hair. “But you can’t just drop a bombshell like that and act like it’s normal!”
“Why does it bother you so much?” Severus asked, his lips curving into a faint smirk. “Are you… jealous, Potter?”
“What? No!” James exclaimed, though the faint pink in his cheeks suggested otherwise. “It’s not about jealousy. It’s just—bloody hell, Sev, it’s Sirius!”
“And?” Severus said, folding his arms across his chest. “It was years ago. Before you and I were even a possibility. Why does it matter?”
“It matters because now I have to go back in there and deal with Sirius being all smug about it!” James groaned, dragging his hands down his face. “Do you know what I’m going to hear for the next month? ‘Oh, Prongs, guess who’s been in my pants and now yours?’” He mimicked Sirius’s voice in a high-pitched tone, making Severus snort in amusement.
“Well,” Severus said dryly, “that does sound like something he’d say.”
“Don’t encourage him!” James groaned. “You already gave him enough ammunition to last a lifetime.”
“You’ll survive,” Severus said, patting James’s arm with an air of finality. “Now, if you’ll excuse me, I have a potion to tend to.”
“Oh no, you don’t,” James said, stepping in front of Severus to block his path. “You’re not leaving me to deal with this on my own. You’re coming back to the common room, and you’re helping me explain to Regulus why his brother is a disaster.”
Severus sighed, clearly unimpressed. “James, your tendency to panic over nothing is truly exhausting.”
“This isn’t ‘nothing,’ Sev!” James insisted. “This is Black family drama! That stuff spreads like Fiendfyre.”
Severus rolled his eyes but allowed James to drag him back toward the drawing room.
---
Back in the Potter drawing room, the scene had descended further into chaos.
Regulus was still sitting in the armchair, staring blankly at the ceiling as if he were questioning every life decision that had brought him to this moment.
“I just… I don’t understand,” he muttered. “Sirius and Snape? How does that even happen? When? Where? Why?”
“Why not?” Sirius said with a smirk, leaning against the back of the couch with his arms crossed. “Snape’s got a certain… je ne sais quoi.”
“Don’t say je ne sais quoi,” Regulus groaned, burying his face in his hands. “You’re making it worse.”
“I think it’s kind of sweet,” Lily chimed in, sitting cross-legged on the floor with Remus and Barty, who were both still laughing intermittently.
“Sweet?” Regulus shot her a look of pure betrayal. “It’s horrifying! My brother… and Snape!”
“It’s not that bad,” Sirius said with an exaggerated shrug. “I mean, it’s not like we’re still at it.” He paused and grinned wickedly. “Unless you want to hear about—”
“NO!” Regulus shouted, pointing a shaking finger at Sirius. “Don’t you dare!”
“Oh, Reggie,” Sirius said with a laugh, ruffling his younger brother’s hair.
“Don’t touch me,” Regulus grumbled, swatting Sirius’s hand away. “I need therapy. And firewhisky. Lots of firewhisky.”
At that moment, James and Severus re-entered the drawing room. James looked frazzled but determined, while Severus looked entirely too pleased with himself.
“Right,” James began, clapping his hands together. “Let’s clear a few things up.”
“Finally!” Regulus exclaimed, sitting up straight. “Please tell me this was all some elaborate joke.”
“Unfortunately, it’s not,” James admitted, earning a dramatic groan from Regulus.
“But,” James continued, shooting a warning look at Sirius, “it’s ancient history. Sirius and Severus were both young, reckless, and probably out of their minds at the time. It doesn’t mean anything now.”
“It meant something to me,” Sirius said, clutching his chest theatrically.
“Padfoot, I swear to Merlin, shut up,” James said through gritted teeth.
“Oh, don’t mind him,” Severus said, his voice dripping with sarcasm. “He’s just bitter because I’m with you now.”
Sirius smirked. “Bitter? Nah. If anything, I’m impressed. You managed to land Prongs. That takes skill.”
Regulus groaned again. “I’m going to Obliviate myself.”
“You’re not going to Obliviate yourself,” Lily said, laughing. “You’re just upset because you didn’t see it coming.”
“Exactly!” Regulus said, throwing his hands in the air. “How did I miss this? How does anyone miss this?”
“Because we were discreet,” Severus said simply, crossing his arms.
“Discreet?” Remus echoed, raising an eyebrow. “You two were literally banned from the astronomy tower because of how not discreet you were.”
Severus didn’t dignify that with a response, though James shot him a betrayed look.
“Wait—you got banned from the astronomy tower?” James asked. “Why am I just now finding this out?”
“It wasn’t relevant,” Severus said with a shrug.
“Not relevant?” James spluttered.
“Oh, get over it, Potter,” Severus said, rolling his eyes. “Or would you like me to recount every detail of my romantic history?”
“Nope, I’m good,” James said quickly, holding up his hands in surrender.
“Thank Merlin,” Regulus muttered.
Sirius, meanwhile, looked positively delighted. “This is officially the best day of my life,” he declared.
Regulus groaned for the umpteenth time and buried his face in the pillow again. “I hate all of you.”
“Love you too, Reggie,” Sirius said, grinning.
As the laughter and chaos continued, James pulled Severus aside, his voice soft. “You’re lucky I love you, you know.”
“I know,” Severus said, smirking. “And for the record, I love you too. Even if you’re insufferable.”
James grinned, leaning down to press a quick kiss to Severus’s lips before they rejoined the group.