Disclaimer: I'm not JK Rowling, so anything you recognise isn't mine.

Warning: Rated M for scenes of a sexual nature (nothing graphic). Also deals with the idea of cheating, so please don't read it you're likely to be offended.

A/N: Written for the Tales of Sin and Virtue challenge at Red&The Wolf on Live Journal - and if you like Remus or Lily, Remus/Lily or Marauder-era genfic, please come over and join us for our next challenge, Tales of Whiskey and Regret. Link to my page is in my profile :).

He sweeps her hair over her shoulder and trails kisses down the back of her neck, revelling in the way her breath comes in snatches, the perfect echo of his own.

His fingers tighten on her stomach, and she presses her body back into his, her fingers twisting in his hair, holding his lips where they are. He duly obliges, hot, breathy kisses down the side of her throat, then across her shoulder, slipping the strap of her bra down as he goes.

Her skin is warm and smells of autumn, and the way she arches back into his touch, resting her head on his shoulder, makes his breath catch in his chest.

He wants to get carried away by this – in this – and she's making it all too easy to forget the reasons they shouldn't be here, but all the same, his lips still on her skin.

He wants to give her one last chance to back out of whatever it is they're about to do while it's just about a pool of clothes at their feet and a couple of frantic kisses, and nothing more…undoable.

He leans in, feels a shiver pass through her, and whispers, "If we do this – " He swallows, because the way she feels beneath his fingers makes him not want to offer any last chance to stop at all, and he watches as her eyes flicker closed. " – we can never take it back."

She takes a breath, opens her eyes and meets his gaze over her shoulder. Her fingers trail down over his neck as she turns, slightly, to look at him, and with her eyes shining in the darkness and the light from the lamppost on the corner casting a faint orange glow on her half-nervous smile, he thinks she's beyond beautiful. He thinks she's staggering, and the blood he thought couldn't buzz any louder burns in his veins. "Do you think you'll want to?" she says, her voice low and laden with a tentative wanting, a desperate hope he won't say yes, and it thrills him. He shakes his head, and smiles. "Good," she whispers. "Me neither."

She claims his mouth before she's even really finished uttering the words, and his blood rushes in his ears and his heart pounds, because this was never going to be something he'd want to take back; but he wanted to be sure, sure that she was sure, sure that in the morning, there wouldn't be regret along with everything else to deal with.

She turns into his arms and he takes her face in his hands, abandons anything approaching rational thought as they stumble towards the bed with her teeth grazing his lip and his fingers in her hair.

He's always been curious about Lily Evans, with her red hair, and her green eyes, and the way she looks at the world as if it's a puzzle it amuses her that she can't quite fathom.

When he looks at her, he doesn't think of her hair as sunlit copper, or count the tones of amber in it, think of metaphors of fire, moths to flames, burned by desire, or anything else a hundred other men and one in particular might have thought about her.

He doesn't think of her in clichés.

He doesn't look in her eyes and see verdant pastures, fresh leaves, emeralds, even. But he does see hope, pure and simple, and when she says things will be all right, he believes her.

When he thinks of her, pictures her – which he does often, and always has, he thinks of the way her smile illuminates her face – which he supposes is a cliché in and of itself – but it does, and beyond that it lights up any room she's in. Or maybe he just thinks it does because it lights up him.

He thinks, too, of the way he longed to see her after every school holiday, especially the endless one in the summer, when she'd come back slightly tanned and he could count the freckles on her nose. Or imagined he could, because in truth he never let himself get close enough for fear of what he might do.

He's not sure how it started.

James is away, Sirius too, and he doesn't delude himself that were that not the case, nothing would be happening at all.

They'd been to a meeting, and after that called in for a drink at some pub. Peter had gone home early because his mother worried if he was out past ten – they'd both said they'd just stay and finish their drinks –

But then she'd asked if he fancied another, and though it had been an innocent question, he'd felt as if he was teetering on the very precipice of something, something dangerous, something unwise, but alluring none the same, something he'd tried not to want, and yet had, anyway. He'd said yes, and before he knew it, they were drinking whiskey and sitting closer than friends should, and her thigh was pressed against his under the table.

They'd talked about nothing – about trolls on the rampage in Devon and some bridge collapse they thought, but couldn't prove, was Death Eater retribution – but none of it mattered, because he knew the same thought pulsed through both their heads, pounded in their veins: they were touching.

And they'd touched before – bumped shoulders, knocked elbows – but nothing like this.

There was intent in it. And they knew – they both knew – that her not moving away the instant her leg touched his, and him not moving away either – meant something. Something thrilling.

The world carried on.

Drinks were served at the bar, conversations didn't stall, no-one even really glanced in their direction, but everything had changed. The air around them felt hot and heavy, and in it was possibility, the possibility to do something that he knew he shouldn't want yet couldn't help but long for, the possibility to know more about Lily Evans, maybe even enough to sate his curiosity.

In a way, he thought they'd been dancing around it for years. Hints, teases, the odd flirtatious look when everyone else's eyes were averted. He'd always kept his distance, but in that moment, when he could feel the heat of her body next to his, see the slight upward turn of the corner of her mouth when he spoke, he wanted to do nothing of the sort.

She'd glanced up and met his eye – and he'd seen in her gaze things he felt sure were echoed in his own: panic that they might be wrong about what they thought was happening, nervousness that they weren't –

But then she'd smiled, and reached for her drink and taken a sip, and he'd done the same, and they'd carried on talking like nothing had happened.

They'd both finished their drinks, and the glasses had sat for a moment on the table next to each other, empty, but somehow filled with other things. Possibility, the idea of no going back, the chance to do something he was certain they both wanted, something that should be quashed by the words 'fiancé' and 'friend', but wasn't and never would be.

He'd toyed with his glass momentarily, tracing the rim with his fingertip, wondering what on earth was going to happen next, and then splayed his fingers on the tabletop, flattening them out in case they were shaking.

He'd thought she'd say something – or that he might, eventually, because it seemed too big a thing for nobody to say anything – but they just sat, and then she'd put her hand on the table next to his, her fingers flattened on the table just as his were, and touched her little finger to his.

And it was such a small thing….

It seemed implausible that just the touch of her finger – and the smallest one at that – to his could cause his body to reel as it did. He'd met her eye, attempted a smile that faltered owing to the pounding of his heart in his throat. He wondered if he should say something dismissive, let this go, or offer a protest, even if it was just a token one, but instead, the words that had formed on his lips were, "Do you want to..?"

She hadn't needed him to finish the question. She'd smiled, and nodded, and got to her feet, and before his mind had had chance to comprehend that this was really happening, they were outside her flat exchanging ravenous kisses against the doorframe.

He'd always been curious about Lily Evans, but up until now, he'd been curious at a distance, using sight alone; not taste, not smell, not touch.

Their bodies press and remit, uttering promises they know they can't keep and confessing the deepest secrets of their souls, if not their hearts, and all the while he knows they shouldn't be doing this, shouldn't have let their curiosity get the better of them.

But all the same, he's glad they have.

She's always been curious about Remus Lupin.

He was always something of a mystery, and however close she sat at school and however much she studied him, things about Remus never got any clearer.

There was always something unknowable about him, and she has the feeling that he likes it like that. Other boys – men, now – she'd been able to fathom with a glance, but not Remus. She always found him curious and curiouser.

There'd always been a distance between them, a tension. He always shifted in his seat when they were left alone together, refused to meet her eye, made awkward stabs at conversation about nothing. Sirius and Peter treated her like they would have any other girlfriend – they laughed and joked and Sirius flirted playfully – they were comfortable with her, but Remus never was, and now she knows why.

He couldn't afford to be.

He felt what she felt.

She'd always wondered….

She liked him, his good manners and his wry humour, his quiet confidence and easy affability. But that wasn't enough, not enough to lead to this.

What lead to this was the idea that she never had the faintest idea what was going on inside him – so many layers to him, and none of them really the truth of who he was. James, James she could read like a book, but the lines on Remus' pages were written in some intricate code she wasn't sure anyone would ever crack.

But she's not curious any more, she thinks.

She can still taste his skin on her lips and feel his fingers pressed against hers, as vividly as if he's still there. She knows every inch of him, and she's seen things in his soul he probably didn't know were there, exposed.

Now she knows.

Now she can marry James, because she's not wondering what if, what it'd be like, her and Remus.

She watches as he pulls on his jeans, and the sunlight catches his hair, and, for a moment, it sparkles. He's very nice to look at naked – nicer, in truth, than she thought he'd be. James is all toned through effort – too much Quidditch – and Remus lacks his definition, and is, if she's honest, rather scrawny, but there's something irresistible about him all the same.

He pulls on his jumper and then glances back, catches her looking.

She smiles, and he returns it, and then reaches for the doorknob.

"Don't I get a goodbye kiss?" she says, and she's only half-joking, only half-putting on the disappointed, slightly miffed tone.

His smile widens, but he shakes his head, and in the next instant, he's gone.

The wedding's a small affair. Mostly it's necessity, but partly she didn't want the fuss.

When she says her vows to James she means them with everything she has to give, because nothing that's happened has changed anything to do with them. She just needed to know, to be certain, because the curiosity, the not knowing would have eaten away at her, and them, and destroyed everything.

She dances with him, Remus, at the reception, and he holds her just slightly closer than he would a friend, but she doesn't mind. In fact, she likes it. He smiles at her with real warmth and affection – more than she'd be capable of in his shoes, and when he says he hopes they'll be sickeningly happy, she knows he means it, and they will be.

She meets his eye and hopes he knows how glad she is that what happened, happened. She's glad, too, that he won't fly into some jealous rage, spill their secret to James, because she knows he's just as afraid of losing him as she is, if not more. She knows that there won't be drama, repercussions, because he feels as she does, that it was curiosity, and nothing more, and now that's gone.

When their dance is over, he leans in and kisses her on the cheek, his lips lingering a little longer than they should, and softly, a little hoarsely, he whispers goodbye in her ear.

A/N: Reviewers get a Remus of their own for their very own tryst ;).