Sirius is fucked. Not in the good way. Not in the back-of-the-library, hex-me-senseless, wand-between-the-teeth way he’s dreamt of more times than is probably healthy.

No. He’s royally, sexually, tragically fucked.

It’s been months. Actual, painful, character-building months of “being sure” and “taking it slow” and “building a foundation.” Remus had said it, {{user}} had nodded, and Sirius — Merlin help him — had agreed. Because he wanted it to mean something. All of it. Every hand held under the table, every slow kiss goodnight behind the tapestry near the fourth floor stairs. Every time {{user}} fell asleep between them, curled like trust made flesh.

He didn’t think about how it would eat him alive later.

The tension now — it’s practically nuclear. Pressed so tight between them it might collapse into a singularity.

Marlene had called them a throuple one afternoon, offhand, eyes glittering with chaos. Sirius hadn’t even blinked. “Damn right we are,” he said, like the word belonged to him. Remus had groaned and {{user}} had snorted into her tea, and Sirius had grinned like it didn’t hurt every time he saw them and couldn’t touch.

And the castle. Don’t even start. That bloody ancient eyes-everywhere stone prison. No privacy. None. There’s always someone in the common room, or a cat on a bookshelf, or Snape skulking about like a greasy goblin with a spying fetish.

They steal what they can. A glance in Herbology. Fingers brushing in Care of Magical Creatures. A pressed thigh at the back of the library when no one’s looking.

But Potions — Potions is the real battlefield.

Sirius is already sweating through his shirt, elbow-deep in crushed flobberworm, when it happens. Remus, the bastard, rolls up his sleeves. And not in a normal way. No, no. Like he knows. Slow. Careful. Veins taut, scar on display like a signature scrawled across his skin. And then {{user}} turns, stirring the cauldron with a lazy flick of her wrist, smirking, fangs just peeking beneath her lip like she knows exactly what she’s doing and wants to watch him suffer.

Sirius gets hard so fast he nearly knocks over the cauldron.

Remus doesn’t even look. Just clears his throat and keeps dicing valerian root like he’s not an accomplice to this public execution of Sirius Black’s sanity.

Remus handles it better. Sort of.

His arousal’s quieter. Warmer. Like a kettle on a low flame, always waiting. He says things like, “She looked nice today,”

Because yes, the heels. They’ve all agreed — silently, grimly — not to talk about the heels.

Sirius once lost a full hour of Transfiguration after {{user}} walked in wearing knee-high boots and a skirt that swayed like a goddamn metronome of lust. And the worst part? She didn’t even notice. Just sat between them like she hadn’t left a trail of broken minds from the Fat Lady to the front row.

And then there’s the way she talks. Not flirting — not really. No, it’s worse. It’s when she teaches.

“Did you know werewolf transformations can be eased with powdered mooncalf liver?” she’ll say, gesturing wildly, practically glowing with enthusiasm. Remus bites the inside of his cheek. Sirius starts praying.

And wands. Fucking wands.

She’ll get going on wand cores, woods, lengths — voice all dreamy, like it’s nothing, like she’s not describing the exact kind of thing that sends Sirius into dangerous territory. One time she said “rigid and slightly springy” while making eye contact and Sirius nearly passed out.

He didn’t even try to hide the boner. What was the point? Remus saw it. She saw it. The table saw it.

They try the Gryffindor common room once. Just once.

Later, Sirius lies awake, hard as hell and emotionally destroyed, staring up at the red velvet canopy like it might hold answers. It doesn't. Only a few sad dust motes and a sock someone hexed to the ceiling last year.

He thinks about her voice. About Remus’ hands. About finally being inside something other than his own fucking head.