"Potter?!" "Black?!"
The Slytherin Dormitory
Some unholy hour – and very much not Gryffindor business
Sirius Black was on a mission. Not a noble, Gryffindor-saving-the-day sort of mission, but a nosy, nosy-bastard, personal-investigation kind. Because frankly, if Severus sodding Snape was doing anything with his baby brother—anything beyond being his weird, greasy little study partner—Sirius was going to lose his entire grip on reality.
So, naturally, the only reasonable course of action was to sneak into the Slytherin dorms under James's invisibility cloak, drag Prongs along for backup, and root through Regulus's trunk like two gossipy aunties.
"D'you reckon they snog?" Sirius whispered as they crept past the fireplace, careful not to knock over the antique snake-shaped lamp. "Like properly snog, tongue and everything."
James grimaced. "Mate, please. I just ate. Let's find whatever we need and get out before we're hexed into next Tuesday."
Sirius ignored him, already crouched by Regulus's bed and rifling through the drawer like a raccoon in a pantry. James took the trunk. It was mostly textbooks, a few carefully organized notebooks, and—to Sirius's dismay—a truly alarming number of very well-kept quills.
"This is tragic. My brother's a nerd," Sirius muttered.
"Mate. Focus," James hissed. "We're looking for evidence, not critiquing his school supplies—"
The sound of approaching footsteps made them both freeze.
"Shit. Someone's coming," Sirius hissed, practically leaping across the room.
"Under the cloak, now!" James yanked it over both of them, dragging Sirius with him into the corner, hearts thudding wildly in their chests.
Just then, the door creaked open. In walked none other than Regulus himself, looking pleasantly exhausted, followed closely by—of course—Snape, who shut the door behind them with all the ceremony of a bloke who thinks he owns the place.
"Just our luck," James muttered under his breath. "The greasy git himself."
"Shh," Sirius snapped. "I wanna hear if he says anything suspicious."
Instead, what they saw was infinitely worse.
Regulus had barely sat down on the bed before Severus practically launched himself at him like a kneazle in heat.
"Merlin!" Regulus wheezed, half-laughing, half-strangled, as Snape began placing slow, deliberate kisses along his neck. "You scared the shite outta me, Sev—"
"Shut it," Severus murmured darkly, catching Regulus's wrist mid-reach. "No touching, baby Black. You don't get to wind me up in front of Evan and walk away like nothing happened."
Sirius's eyes nearly bugged out of his skull. "Baby Black?!" he mouthed furiously at James, who was already hiding his entire face in his hands, clearly re-evaluating every life choice that had led to this moment.
Regulus moaned softly, letting his hand fall as Severus undid his tie with deft fingers. "I wasn't—" he tried to protest, but Severus cut him off with a rough kiss.
Sirius stared.
James looked violently ill.
"Oh my Godric," Sirius whispered. "They're—he's—Reg's the bottom! Prongs, he's the bloody bottom—"
"Shut up shut up shut up!" James breathed, jamming a hand over Sirius's mouth, eyes wide with pure trauma.
But it was too late.
Severus immediately stopped, stiffened, and looked around with the sharp alertness of someone who knows exactly what a whisper sounds like. His eyes swept the room.
"Did you hear something?" Regulus asked, sitting up a little.
Severus didn't answer right away. "...We should go to my dorm," he said at last, eyes still scanning the shadows. "I'm not comfortable here."
He leaned in to kiss Regulus softly before helping him adjust his tie, then led him toward the door. Regulus looked mildly confused but followed without protest.
Sirius didn't breathe again until the door clicked shut behind them.
James tore off the cloak, his face pale and mortified. "We need to get out. Now. Before I die of second-hand embarrassment."
"I'm gonna bleach my eyeballs," Sirius muttered. "I just watched Snivellus make out with my baby brother."
"We need to set the whole dormitory on fire, then run." Sirius said, dramatically
They made it halfway to the door before it opened again—and there they were. Regulus and Snape, standing frozen, looking like they'd just caught two rats in the pantry.
Sirius and James stood stiffly, caught red-handed. Everyone stared.
Regulus was the first to speak, voice icy cold. "What the fuck are you two doing in my dormitory?"
James opened his mouth. Then closed it. Then opened it again.
"I—erm—homework?"
"Oh, bollocks," Regulus snapped. "What kind of homework do you do in the Slytherin dorms, with an invisibility cloak?"
Severus was glaring, hands twitching near his wand. "You broke into a student's room and spied on us?"
Sirius, for once, had no clever comeback. He was staring at Regulus like he'd been personally betrayed by Godric Gryffindor himself.
"You—you let him call you 'baby Black'?!" he finally burst out, voice cracking with pure horror.
Regulus blinked. Then shrugged. "Yeah. Got a problem with it?"
James nudged Sirius. "Now's really not the time."
"No. No, this is—this is treason, Reg. What would Mum say?!"
Sirius looked like he might actually combust. "I am going to vomit."
Regulus rolled his eyes, stepping aside and gesturing to the door. "Then kindly do it somewhere else."
James grabbed Sirius's arm and pulled him toward the hallway. "Right. Cheers. Lovely seeing you both. Hope you two enjoy... whatever that was."
Sirius, still reeling, glanced back one last time.
"Baby Black, though?!"
The door slammed shut behind them.