Pairings: Remus/Sirius, James/Lily
Rating/Warnings: Sexual situations, language, descriptions of violent acts/deaths
Notes: Magical AU written for the Marauder Big Bang at Livejournal. This is complete and will be posted in 10 parts. If you'd like to read the whole story at once, please see my profile for a link to my LJ page. From there, you can find the post leading to the Marauder Big Bang. Thank you to my beta and inspiration, dogsunderfoot for her help and support, and to brighty18 for going above and beyond the call of duty to get this fest back on track.
Disclaimer: Harry Potter and all characters, places, objects, ideas, and related material are the property of JK Rowling and her various publishing entities. Neither the author, the artists, nor the marauderbigbang are in any way making a monetary profit from this posting.

'Morning, all!'

'Shhh!'

Sirius came to an abrupt halt just inside the Potter house, staring at James and Peter in consternation. 'What?'

'The baby's asleep,' James hissed, while Peter glared at Sirius. 'Keep your voice down.'

Sirius looked from James to Peter with raised eyebrows and stepped into the room. 'Okay,' he said, drawing the word out. 'When did you two become the fun police?'

'When Lily turned into a hormone-driven nut case,' Peter muttered, wincing at the elbow James planted in his side.

'Lottie hasn't gotten the hang of sleeping just yet,' James told him, flopping into an armchair. 'We're buggered... and not in the way you enjoy,' he added when Sirius opened his mouth to contribute a lewd comment.

Sirius laughed and sank down on the couch, Peter collapsing next to him. 'So, I'm guessing you don't want to hear about the bloody incredible sex I had last night,' he taunted, grin widening when James glared daggers at him.

'Sex... Gods, I remember sex,' Peter moaned, slumping back against the cushions. 'I'll take the bait. At the moment, I'm so bloody desperate that I'll settle for living vicariously through you.'

'I've been pretty hard up as well,' James broke in. 'Hello? Pregnant wife threatening my nads every time I looked at her? But I'm still not so desperate that I want to hear about your night of debauchery with some stranger you picked up in a bar.'

'Oh, it wasn't a stranger,' Sirius said with a smirk. 'You know him – although I did originally pick him up in a bar. Or did he pick me up? Don't quite remember.'

'Sirius!'

'Right,' Sirius said, laughing at Peter's frustrated expression. 'It was Remus Lupin.'

'Who?' Peter asked, puzzled, but James sat up ramrod straight.

'Remus Lupin?' he exclaimed. 'As in Harry's tutor?'

Sirius just grinned, and James groaned. 'Oh, no, no, no,' he mumbled, shaking his head. 'You cannot shag one of Lily's friends. You just can't.'

'You're shagging Harry's tutor?' Peter asked, looking curiously from one man to the other.

'Yep,' Sirius said, triumphantly.

'No,' James insisted. 'Sirius, Lily loves this bloke. Seriously, she loves him so much I was actually a bit... jealous until she told me he was a member of your club. You can't fuck around with him.'

'Why not?' Sirius asked in confusion.

'Because you never have serious relationships,' James declared with a dramatic flourish. 'Because if you upset this Remus bloke, Lily will want your balls and she will force me to participate in removing them.'

'Remus is a big boy,' Sirius told him, winking in case James didn't get the double entendre. He did, hiding his face as he groaned. 'He knows what he's doing and can look after himself.'

'Remus? Tell me you are not talking about Remus Lupin?'

All three men turned towards the staircase, seeing a pale-faced Lily standing half-way down, her arms crossed over her chest.

'Oh, she's gonna kick your arse now,' James muttered.

'You didn't sleep with him?' Lily asked, ignoring James as she stared at Sirius intently. 'Sirius...'

'Lil, I adore you as much as I possibly can considering you possess body parts that make my cock shrivel up, but who I shag has nothing to do with you. Remus is a grown man...'

'You can't see him again.'

Sirius was taken aback by the determination in her voice. He looked over his shoulder at James, who looked equally as startled.

'Lily...'

'I mean it, Sirius,' she said, her voice cracking a little. 'There are things...' She bit her lip. 'Please? Don't see him again.'

'Lily,' interrupted James. 'It really is none of our business.'

'Trust me, Sirius,' she said, continuing as if James hadn't spoken. 'Nothing good will come from this. You could both be hurt very badly.' She came down the stairs and cupped Sirius' face. 'This won't end well for either of you.'

Sirius frowned. He'd known Lily for over a decade. She was hiding something. 'What aren't you telling me?'

Lily shook her head. 'It's nothing,' she said, face pained. 'But I know you, and I know Remus, and this has disaster written all over it.'

'It's just sex, Lily.'

'It's never just about sex with Remus,' she told him, a tiny smile on her face. 'He doesn't do anything casually. That's why you should stop this now before you both get in too deep.'

She kissed Sirius chastely on the top of his head before heading into the kitchen. The trio sat in silence for a moment before Peter and Sirius turned to James.

'What the hell...?' Sirius began, but James held up his hands defensively.

'I don't know,' he said, looking as confused as Sirius. 'I... She knows Remus pretty well. I guess she thinks you aren't compatible.'

'It's just sex!'

'Then does it matter if you see him again? Just pick up another bloke next time you're out,' Peter suggested then yelped in surprise when Sirius rounded on him.

'She has no right interfering in my life,' he hissed, and Peter shrugged.

'Well, maybe it's not your life she's concerned about,' he suggested. 'She's friends with this Remus. Maybe she thinks he'll want more than sex and it'll be one big mess.'

'Harry can't stop raving about this bloke,' James broke in. 'If things get... messy, I don't want him upset because you fucked the wrong man.'

Sirius threw up his hands then pushed himself to his feet. 'Look, it was one night. Well, one night plus that... thing at the club, but this isn't a love story. This is sex. Fucking spectacular sex, but just sex.'

'So leave him alone and find someone else,' James said, standing also. 'Look, Sirius. You know Lily, and you know she wouldn't ask you to do this without a reason. Maybe she's right.'

Sirius shifted uncomfortably. James and Peter were right. It really shouldn't matter who he got off with, but Remus - him and Remus together - were bloody incredible, and he wasn't ready to say goodbye to that without a good reason.

'Yeah, maybe,' he grumbled, avoiding meeting James or Peter's eye. 'Look, I'd better go. I'm on my lunch break, and we've got that case...'

'The murder case? At the Muggle gay bar?' Peter asked, and Sirius glanced at him.

'You know about that?'

Peter nodded. 'Moody contacted me and asked me to look at the second victim. I'm heading to the morgue now, if you want to tag along.'

'Sure.' Sirius reached out and cuffed James around the head. 'I'll see you later. Give the kids a kiss for me.'

'Sirius...'

'Tell Lily I'll think about it.'

James rolled his eyes. 'I plan on staying well away from Lily this afternoon,' he muttered. 'You know I'm going to be punished because you can't keep it in your pants?'

Sirius smiled as he followed Peter out of the house. 'And that is why I shag men.'

Peter poked at a long, jagged slash across the dead man's chest, making Sirius grimace. 'Pete,' he murmured in disgust.

Peter looked up and chuckled, glancing back down at the body then making a note on a file. 'It's not as gruesome as it seems,' he told Sirius, who was looking a little green. 'This kind of work is actually really interesting.'

'Whatever turns you on,' Sirius muttered. 'Are you drawing any actual conclusions or just getting off on playing with a dead man?'

With a sigh, Peter turned to Sirius. 'It was a werewolf that did this,' he said baldly. 'These slashes in the skin... They're distinctive, Sirius. The bite marks aren't complete – the victim must have struggled, causing the skin to tear - but it's conclusive enough.'

'Godric,' Sirius muttered, running a hand through his hair. 'So there's a werewolf loose in London.'

Peter frowned at the body. 'It's odd there's been only one victim found each time,' he mused. 'You would think this bloke wouldn't have been the only person around, and there's no evidence of attempted... consumption. If the wolf was hungry and killing for food, I would have expected to see more missing parts.'

'I researched werewolf behaviour when I was trying to get that lockdown legislation repealed,' Sirius told him. 'There is anecdotal evidence that they don't always hunt as indiscriminately as everyone thinks. I mean, yes, a hungry werewolf will kill anything edible in it's path, but there might be a case for werewolves being able stalk a chosen victim.'

Peter looked unsure. 'I thought that werewolves lost control of their minds during the full moon?'

'They lose control of their human mind,' Sirius corrected. 'There was a case - twenty years ago now - where a werewolf appeared to have hunted down the child of a Ministry worker that did him wrong. He bit the child and turned him. It seemed to be deliberate targeting. He chose his victim. I don't know how, but it can happen, I'm sure of it.'

'What happened to the child? Did he survive?'

Sirius shrugged. 'I don't know. The family disappeared after snatching him from St. Mungo's.' He sighed. 'So potentially, we have a werewolf that is targeting gay men roaming freely through London on the night of the full moon. I need to do some more research. If I can figure out how they track their victims, I might be able to stop another attack.'

Peter frowned. 'There's a full moon tomorrow night,' he said doubtfully. 'That's not a lot of time to get ready.'

'I know. I'm going to organise a stakeout at 'Skin', but if we could figure this out before then...'

Peter turned back to the dead man, pulling a sheet over his mutilated body. Sirius watched in relief as he levitated the man back into his stasis chamber. 'Pete,' he said suddenly, his mind wandering back to the altercation at the Potters'. 'Do you think Lily's really worried about Remus getting too serious? Or do you reckon she might have a bit of a crush on him?'

Peter laughed, washing his hands quickly then drying them off on a towel as he turned to smile at Sirius. 'I think that Lily likes this bloke and doesn't want him to get hurt,' he replied then he tilted his head curiously. 'You don't usually go back for a second go at your club conquests. You like this Remus bloke?'

'If I didn't like him...'

'I don't mean like as in you like his tight arse and big cock,' Peter interrupted. 'I mean, you met him by accident after your first fumble and liked what you saw enough to arrange to get together again. Even if it was just for another shag, you've never done that before.'

'He was a good shag,' Sirius shrugged.

Peter snorted. 'You've had good shags before,' he said dismissively. 'I should know; you make us listen to every single detail of each encounter. Look, if Lily says this bloke doesn't do casual very well, you should be running a mile. Instead, you're resisting dumping him and moving on. That's not like you.'

Sirius scowled, and Peter raised an amused eyebrow. 'Just making an observation,' he said placatingly.

'Yeah, well, don't,' Sirius muttered in irritation, turning on his heel and stalking towards the door. Peter didn't say a lot usually, but when he did, it was often spot on. A little too spot on for Sirius' comfort right now.

Concentrate on this case. You won't have much time for any kind of shagging until it's over.

'I'd better get back to work,' he said as he reached the exit. 'See ya.'

'Let me know how you go with this case,' Peter called after him. 'I'm curious now.'

Sirius waved an acknowledgment and turned on the spot, Apparating back to the Ministry to spend the afternoon researching and very deliberately not thinking about Remus Lupin.

TBC