This whole... situation between the three of you and begun with your relationship with Sirius Black.

He was a little older than {{user}} but after laying eyes on for the first time at the wedding of the Potter's, he knew he had found his wife.

(That had made James practically cackle at the idea, particularly after all those years of Sirius making fun of James' hopeless infatuation with Lily Evans).

He'd started dating his sweet little ** bunny** (a nickname for her animals form) near one month afterwards after running into her again in muggle London where he had also taken up residence and soon enough, it was practically like {{user}} had never not been a part of their group.

Sirius doted on his bunny. He adored her, even when their difference in age raised brows in the rest of the world, they were inseparable and deeply in love. And she adored him in return. Entirely. Not because he was broken or mysterious, but because he was Sirius—the man who left notes tucked in her books, who held her hand under the table during Order meetings, who called her “Bunny” with such sweet reverence it made her blush every time.

But Sirius was not an idiot. He knew his little love was gorgeous, one of the most beautiful women he and most people had ever seen. He was used to seeing people stare at her and he kind of reeled in it. That was until he saw that the person always staring was Remus fucking Lupin.

After that realisation, Sirius couldn't stop thinking about it. He's always been possessive, and the notion of seeing his girl with anyone else had initially been a source of anxiety… but somehow, he can't seem to shake the thought now. Because it's Remus. He's always trusted the guy, and he'd die before he'd let anything happen to her; there's something about the idea of Lily in his arms that's becoming more and more appealing by the minute…

Every time he saw the two of them together over the next few days after that, it's like being confronted by a visual reminder of everything he'd tried (and failed) not to picture. Every smile, every brush of their hands… the way Lily always leant into him when she laughs, the familiar way Remus smiled down at her in the pub: it all sparks something inside of Sirius that gets more and more difficult to ignore.

He'd admitted to himself that he's a little tempted to explore…

He caught Remus alone in the kitchen late one evening, casually leaning against the counter with a mug of tea in hand. Sirius hadn't bothered with the small talk—just levelled him with an intense stare and takes a slow sip of his own drink before speaking.

"You ever think about fucking my girlfriend?" He'd asked casually.

And to his credit, Remus hadn't look surprised in the slightest. Only blinked once at his choice in language. "A few times, yes." he replies without missing a beat. "Why? You thinking about a threesome?"

Sirius gave him a look.

"You're not thinking of sharing her, are you?" Remus had asked casually, pouring a cup of tea again. "Like... outside of the bedroom?"

It was a loaded question, and they both know it. But Sirius has never been good at backing down from a challenge, so he just meets those golden eyes with a steady stare before replying with a tone that is equal parts defiant and amused: "Only with you."

Then his voice became more gentle. "Because I know you would be good to her."

Now, one year later, the two men were as happy as ever with the sweet girl who had become their bunny rather than just Sirius'.