Remus Lupin's apartment is a lot like Remus himself – shabby and foreign but with a sense of warmth that one would associate with the word 'home'.
When Sirius first walks into it he looks strangely out of place, far too erratic, far too twitchy, far too on-edge compared to the calmness of his surroundings.
They tiptoe around each other for the first few days, Remus afraid that he may touch something that might cause him to explode. Even after everything it seems awkward and there's a voice in Remus' head saying it shouldn't be like this. Humanity has always been a sort of an enigma to Remus but even then – he just can't comprehend how two people who once knew every inch of the other can walk around a house as though they were mere acquaintances.
Sirius is different. It scares Remus, at first, how time can change a person so much that you can barely recognise who he is anymore. He wonders if that intimacy, that dependency even means anything anymore if time has changed them both so much that all that once existed was important to a different person. He wonders if the fact that it mattered once still makes it matter now.
But he watches Sirius, who either sleeps too much or not at all, who either paces for hours or sits staring out a window for days, and he knows. He knows because this Sirius, this Sirius Black who has been stripped to the core, is still the ultimate paradox, still either black or white with no shades of grey. And it kills him, it destroys him to see Sirius like this, but the rawness of it all is so characteristically Sirius that he can't help but get comforted by it.
Remus cooks Christmas dinner for the first time in his life. Sirius doesn't expect him to, but Remus feels like if they fake normalcy for long enough they just might get there.
They make a big show of wearing fancy robes and taking out the best cutlery Remus can actually afford before sitting formally at the table.
'You know, you're still an absolutely terrible cook,' Sirius says with a smile.
'Perhaps it's just your taste buds. Not all of us are accustomed to fancy pureblood cuisine, you know.'
They smile at each across the table, and Remus is suddenly filled with an urge to cry because of how familiar this all feels, how comfortable it is to talk in that back-and-forth motion that was once so characteristic of them.
They wash the dishes together before settling down on the couch to watch the muggle news. Remus is almost entirely absorbed in a book when Sirius reaches over and kisses him.
It feels hesitant, almost as though Sirius is asking permission with his tongue, almost as if what they're holding between them as they kiss is so fragile that any sudden movement will cause it to break. And then, far too soon, Sirius pulls away.
Remus meets his eyes for a second, opens his mouth as if to say something before changing his mind and pulling Sirius in for another kiss.
Remus has always hated nostalgia, always resented it for convincing him of how much better things used to be. Because how could they have been better, if things turned out the way they did? How could they have all been 'best friends forever' if, towards the end, all they saw was 'werewolf'? How could they have been made for each other when their thoughts had shifted to the word 'traitor' at the first chance?
But this, God, this was proof. The way their mouths fit together like puzzle pieces was proof. The way their tongues slid against one another in that familiar rhythm was proof. This was all proof that what they had, what they all had was so remarkable that nothing could ever compare to it. Nothing could ever erase it.
Remus wakes up the next morning to cold fingers tracing the scars on his spine.
'There are new ones,' Sirius whispers. 'I don't know these ones.' He's propped up on the bed against his elbow, and the way his hair casually falls across his face makes Remus feel like he's going to explode.
'Well,' says Remus softly, 'you'll get plenty of chances to make their acquaintance. I promise.'
'I love you,' says Sirius.
It doesn't sound like the very first time he said it at the top of the astronomy tower, making a very dramatic show of something they both already knew. It doesn't sound like the morning after their first time, when Sirius looked like he might explode because of how lucky he was. It doesn't sound like when Sirius asked him to move in with him, filled with a nervousness no one even knew Sirius had. It doesn't sound like the day he said it at James and Lily's wedding, filled with enough hope and promise to convince Remus that it was going to be like that forever. It doesn't sound like the very last time he said it, filled with an insistence to be proven wrong that Remus didn't comprehend until years later.
It sounds like a fact, a mere declaration, erasing the passage of time and the new scars on Remus's body and the unfamiliar wrinkles on Sirius's face. It sounds like there was never any doubt at all.
'I love you too,' says Remus. And then he says it again, and again, and again, clinging on to every second that considers him worthy enough to have the chance to say it.