So this is actually my first ever Sirius/Remus fic, and I managed to actually not put any romance as such in. It's a whole load of angst and tears, you have been warned.

Inspired in part by a conversation with a friend, the idea for the fic came to me while I was making coffee this morning and developed from there. The title is, of course, from Paramore's Let The Flames Begin.

I don't own Harry Potter, or the characters seen in this fic. None of them.

x

Remus knew better than to ask.

So when Sirius collapsed into his bed in the early hours of the morning, stinking of alcohol and cheap pubs and cigarettes, and slurred a muffled I need you, Remus just rolled over and buried his head in Sirius's shoulder, muttering a quiet prick as he did. Sirius laughed softly and wrapped an arm around the slender man, tugging him closer, and they fell asleep like that. The explanations could wait for when they were both awake. And sober.

The next morning saw them both standing in the kitchen in the flat they shared, facing each other. Sirius was nursing a cup of tea in both hands, twisting it around slowly and watching the steam rise from the scalding liquid. Remus sipped at his coffee - black, two sugars - and watched Sirius.

"How bad was it this time?" he asked softly after a while, and Sirius sighed, placing the cup down on the table behind him.

"I've been worse," he replied, brushing his bangs off his face and rubbing a hand across his morning stubble. Remus grimaced.

"Not much worse." Sirius didn't disagree, and Remus looked down into his nearly empty mug.

"No," the Black boy muttered a moment later. "Not much worse." His lips quirked slightly as he said it, as though it was some kind of private joke.

"It's been almost three years now, Sirius." It wasn't a rebuttal or a reprimand or a demand. It was just an acknowledgement of a fact. "James is going to propose soon. He asked me to help pick out the ring."

Sirius's head shot up at that, meeting Remus's steady gaze. He swallowed softly, his hands clenching and then relaxing, smoothing down the front of his crumpled shirt.

"He... asked you? To help?" And underneath the simple words was an accusation of sorts - why you? Why not me? I'm his best friend.

"I'm 'better at that sort of thing', apparently. I think it was Lily's idea." Remus just kept watching Sirius with his even gaze, completely without judgement, just like it had always been.

"Right, of course." Sirius flushed anyway, ashamed of his quick leap to betrayal.

"Did Peter take you out again last night?" Remus changed the subject gently, and Sirius felt a rush of gratitude run through him, quickly followed by guilt. Remus was so understanding, so accepting, and Sirius just took full advantage of that. He knew it wasn't fair, but he didn't know how to stop.

"Yes," he replied softly, reaching behind him to grab his tea and taking a quick gulp as though it would erase the night before, so he didn't have to see the flash of disappointment in Remus's eyes. He knew Remus hated it when he went out with Peter. It always ended in a drunk Sirius, usually angry but sometimes weepy - either way, he was horrible to Remus when he stumbled home. The night before he'd been too tired, too worn out, to fight. He was grateful for that at least.

"It could have been worse, I suppose," Remus said quietly, and the thoughts behind the statement were clear, hanging awkwardly in the silence between them. It has been worse. So much worse.

Remus sighed softly, turning to the sink and busying himself with the warm water, rinsing out his mug and placing it upside down on the drying rack. He didn't look up at Sirius, didn't speak to Sirius, and the Black boy stared at Remus's tense shoulder and defeated stance, feeling the regret build up in him, just like it always did.

"I'm sorry, Remus," he murmured, dropping his gaze to the now lukewarm drink between his hands. He still felt Remus stiffen, felt the tension that built up in his friend. He knew it wasn't enough, but he didn't know what else to say - or how to say it without sounding insincere.

"I know, Sirius. I know." Remus sounded so tired, so much older than his twenty years. It was the war, and the transformations, and Sirius. He knew it was partly his fault, and he hated himself for it.

Remus leant over the sink and shut his eyes, trying his hardest to forget Sirius was standing there watching him. His hands clenched on the edge of the basin, knuckles turning white and fingers pressed into the metal.

It was scary how hard everything had become since they'd left school, two years earlier. It was scary, thinking how much they'd all changed whilst at the same time staying exactly the same.

It was scary how much further he'd fallen for Sirius.

It had seemed like a good idea at first, sharing a flat with Sirius. James moved in with Lily, and Peter was staying with his parents while he saved money to train for a job in the ministry. Only he and Sirius were left with nowhere to go, no jobs, and barely any money. The cheap, two-room flat in London had been the logical idea. James encouraged the plan - and, of course, that sealed the deal for Sirius, and Remus went along with their scheme. Just like Hogwarts.

But James had always been oblivious. He'd proved that a hundred times over, from their fifth year and onwards, as he steadfastly failed to notice Sirius's desperate crush on him, even as it progressed into full-blown unrequited love. If he couldn't see that, then how could Remus expect James to see how he felt about Sirius? How could Remus expect James to see the thousands of ways living with Sirius could kill him?

So he moved in with Sirius, because it would make them happy, and tried his damndest to shield away his heart so he wouldn't get hurt.

Needless to say, it didn't work. It never does.

And now he was losing Sirius. He could feel his friend pulling away, feel him slipping out of reach, helped along by Peter's nights out and cheap beer. He was losing the one person he wanted to keep, and he didn't know how to get him back.

Taking a deep breath to steady himself, Remus blinked away the anger and the hurt and the fear before turning back round to face Sirius again.

"Are you working today?" he asked, hands tightening on the sink as he met Sirius's eyes.

"Not until the afternoon, Priestly gave me the morning off." Sirius's gaze was intense, his eyes burning into Remus's, but Remus forced himself to hold it. He could be strong - he had been strong all his life, after all. They would make it through this. They had to.

"Oh." Remus had banked on Sirius being in work all day. He was going to clean the shack, try and get rid of some of the bloodstains he'd left last time he was there. It would be a full moon again in less than a week, and the smell of blood made Moony worse, less controllable. "Okay. What are you going to do?"

Sirius cocked his head ever so slightly to the right, a doggish trait that he'd only picked up in the sixth year, after he and James and Peter taught themselves to become animagi. Just another thing Remus blamed himself for. He studied Remus for a while, his eyes bright, and smiled slightly.

"I thought I might head over to your monthly haunt, see if I couldn't freshen it up a bit." And, just like that, the conflict inside Remus began brewing again, because he'd be damned if it was simple things like that that reminded him why he loved the other marauders so much. Especially Sirius. "Reckon I might need your help though, it's not exactly a one-man job."

I'm not letting you do it by yourself, he was saying. And; I know I'm an idiot, but I do care, see?

Remus nodded, lifting one hand to run it through his messy hair and dropping his eyes to the floor.

"Alright," he agreed quietly. And then, glancing back up at Sirius, "thank you." Sirius shook his head, a smile gracing his features.

"You don't need to thank me," he told Remus. "It's what friends are for, right?"

"Right," Remus muttered, and if Sirius noticed the bitterness in his voice, he didn't comment.

They apparated to the shack. It was easier than floo, and no other methods of transport would get them there fast enough, so they apparated even though Sirius hated it.

Hogsmeade looked beautiful in the summer sun. Behind them rose Hogwarts, huge and impressive, the sunlight glinting off of the windows and the towers. The school was empty, all the students and teachers at home for the holiday - Remus included. The whole place was eerily silent.

The shrieking shack looked the same as it always had. The sun couldn't seem to chase away the shadows that shrouded the house, and Remus shivered slightly as they approached. The dusty old house held too many bad memories for him to feel comfortable near it, even in pure daylight, with the full moon five days away.

Sirius glanced over at him and paused, startling Remus into looking back at him.

"You don't have to come, Remus," Sirius said softly, holding out a hand as though to touch Remus, then thinking better of it. "You can go, if you want. I know you hate it here."

"I'm okay, Padfoot," Remus replied, hoping that the use of Sirius's nickname would convince him. "I can deal with a few bad memories, right?" He forced a smile, which Sirius returned dubiously.

"If you're sure..." he murmured, watching Remus with worried eyes.

"I'm sure, Sirius. Let's just get this over and done with." Sirius hesitated for a few more moments, so Remus turned and pushed open the door to the shack, stepping into the gloom. Sirius followed seconds later.

The room was a mess. They'd left no furniture in the room Remus shut himself into, but the threadbare carpet had been ripped out and thrown to one side, where it lay bunched up against the wall. There were bloodstains smeared across the walls and the floorboards; dark brown messes against the greying wallpaper. Sirius hissed slightly from behind Remus and stepped to one side, brushing his palm across a stain at head height.

"Merlin, Remus. What happened?"

What happened had been anger - Remus's anger amplified over and over by Moony's aggression and animalistic rage and taken out on himself because he'd refused to let the others stay with him that night.

"I was mad, and Moony was madder," he told Sirius softly, stepping into the centre of the room and scanning his eyes across the opposite wall.

"You knew," Sirius accused softly. "You knew it would be a bad night. That's why you didn't let us stay. Remus, you know you can't do that." Sirius's voice almost broke at the end, but Remus kept his back to him, eyes fixed on a dark mark roughly the size of one of Moony's paws.

"I was trying to keep you safe," he explained, hands clenched by his sides. "I can't let you get hurt."

"But what about you, Remus? What about keeping you safe?"

"You wouldn't have been able to do anything. I was too angry, too wound up. I wouldn't have recognised you, and even if I had, it wouldn't-" the sentence hung, unfinished in the air between them, but Sirius was smart. Sirius had always been smart, always able to work out what Remus wasn't saying.

Even if I had, it wouldn't have made a difference. Moony would've attacked you anyway. It was you I was so angry at.

Sirius had fucked him. Sirius had fucked him because he loved James but he couldn't have James, so Remus had been the next best thing. And Remus knew that. And Remus had hated himself for it, but he'd hated Sirius more, because Sirius was supposed to be his friend. And it had been the night before his last transformation, and he'd known that Moony would have ripped Sirius to shreds if Sirius came anywhere near him that night.

"I'm so sorry." This time Sirius's voice did break, a sob hitching the words as they fell out of his mouth. Remus turned, instinctively, at the sound of his best friend crying, and the sight of Sirius kneeling on the floor, his hand pressed into a bloody handprint on the wall, hit him like a blow to the stomach. "I am so very sorry, Remus. For everything. For the way I treat you, and the way I feel, and the way I can't love you back. I'm sorry."

There were tears on both their cheeks as Remus dropped to his knees behind Sirius, his head shaking and his hands trembling.

"I would do anything," Sirius breathed, "anything to make you happy. Because you deserve it more than anyone else. And I'm trying, Remus. I am. I know I can't have James, I do, I just need to work out how to stop. Stop wanting him, stop hurting you, just stop it all."

And Sirius turned his head to look at Remus, twisted his body and pulled himself closer, reaching a hand out to Remus's face.

"I want to love you, Remus. I know it's not enough, but I will love you someday, I'm sure of it. Maybe I already do, I just can't see it. I'm searching for it, and I'll keep searching until I find it, I promise. I've asked so much of you already, and it's not fair that I have to keep asking, but I need you to wait, just to be patient a little bit longer, please. I'm sorry, I know it's wrong, I do, but I can't do this without you. I'm sorry, Remus. I'm so, so sorry."

Remus knew what he should say. He knew he should push Sirius away, tell him no, stop waiting for the impossible. But he'd never been able to say no to Sirius, and the desperation in his voice and his eyes and his touch had shut down Remus's mind. Slowly, he reached a hand up and placed it over Sirius's, on his face, and nodded once.

Sirius's whole body collapsed, arms dropping around Remus and head falling into his shoulder. Remus wrapped his arms around Sirius and held him tightly, his face buried in Sirius's hair as his tears burned his eyes and his cheeks.

"Thank you," Sirius murmured into his shirt, body shaking. "Thank you."