You hated this house.

You didn’t say it out loud, of course. You were far too polite for that. Too gentle. But Regulus could tell. It was in the way your nose crinkled whenever Kreacher slunk past mumbling dark things under his breath. In the way your fingers hovered over the cursed banister like it might bite.

You didn’t belong here.

Which made you all the more fascinating.

You were Sirius’s girlfriend. Which, on principle, meant Regulus should dislike you. That was the rule — anyone Sirius brought home was loud, reckless, fleeting. He collected people like cigarette burns and burned through them just as quickly.

But then you came.

And you were… not what Regulus expected.

You were kind. Too kind, probably. You said good morning to Kreacher. You made tea for Walburga once, even though she didn’t drink it and snapped at you for touching her kettle. You tiptoed around the edges of everything — including him. As if you knew he might shatter if you got too close.

It was unbearable.

And yet — you stayed. For Sirius.

Which meant Regulus had to watch. Had to listen to your laugh echoing through the halls. Had to see the way you curled your fingers into Sirius’s robe when he kissed you in the foyer. Had to sit at dinner, fork idle, as you told some story about Gryffindor tower that made Sirius throw his head back in laughter — and made Regulus feel something he couldn’t name.

And worse — you tried to befriend him.

You’d knock on his door with a book in hand and ask, “Have you read this one?” You’d sit near him in the drawing room and ask little questions: How’s Slytherin this year? Do you like Astronomy? Want tea? He’d answer in a single word, if that.

But you never stopped trying.

And that — that was how you got under his skin.

One evening, the three of you were in the library. Sirius was half-asleep, sprawled in a chair, muttering something about how books were a crime against fun. You were curled up on the floor by the fire, a blanket around your shoulders, reading The Tales of Beedle the Bard aloud in that soft voice of yours, like magic lived in your mouth.

He was meant to leave. He always left when Sirius was there.

But he didn’t. He sat on the floor near the opposite bookshelf, pretending to read some dusty volume about ancient magical lineages.

You paused in your reading to look at him. “Regulus?”

His name sounded different when you said it. Not like a challenge. Not like an insult. Just… a name. His name.

“Hmm?” he murmured without looking up.

You smiled — he could hear it in your voice. “Do you like this story?”

Regulus exhaled slowly. “It’s a fairy tale.”

“Fairy tales can be true, you know.”

He did look up then. Something about the way you said it — so matter-of-fact, like truth could be soft and shimmering and worn into the shape of a wish — it knocked something loose in his chest.

You weren’t just Sirius’s girlfriend. You were yours. You. And you were ruining him.

He didn’t answer.

You returned to your reading, unbothered by his silence.

And Regulus watched the firelight flicker in your eyes, and told himself it didn’t mean anything. That you were just polite. Just curious. Just there because of Sirius.

And yet—

Later that night, long after Sirius had fallen asleep beside you on the couch, your head on his shoulder, Regulus walked silently back through the darkened halls of Grimmauld Place.

The next morning. You and Regulus ended up in the same room again — breakfast, surprisingly civil. Sirius was still upstairs, probably asleep.

You stood awkwardly near the teapot, glancing at Regulus, unsure.

“Do you… want some tea?” you offered, voice careful.

Regulus blinked, looked at you, then — against all instinct — gave a tiny nod.