A/N : I've been re-watching some of Season 4 BtVS of late and I had this crazy idea for a fic. I was going to wait to write it but I just couldn't so here is the first chapter. Not sure yet how long this is going to be, I'm just going to go with it and see what happens. I apologise so much to readers of 'Life's Full of Surprises' and 'Innocence', I promise I will try to write some more on both of those soon, but right now I just have to go where my muse takes me, I hope you understand...

Title : Our Little Secret
Rating : PG-13
Spoilers : Season 4.
Summary : AU Season 4. Spike is starting to notice the Slayer is acting strangely. Buffy herself hasn't been feeling so good of late. When they both find out the reason, can they keep it to themselves...?
(Timeline-wise this takes place from the end of 4.11 Doomed onwards but it's AU so not all the events of the mid-to-late Season 4 will be included)
Disclaimer : Joss owns all things BtVS related.

Chapter 1

"I don't know why I let you talk me into this?" the Slayer complained as she strode through the graveyard with Spike at her side. A few hours ago the vamp had realised that despite his inability to hurt humans without a severe pain to the head, he was quite able to beat on demons. All he wanted to do was get out there and kill something, and when Willow and Xander had not been forthcoming he'd called on the Slayer, and Buffy reluctantly admitted she was planning to patrol anyway. She let Spike tag along, figuring he might be useful but really not happy about having to spend time with him.

Ever since that spell Willow had cast things had been a little weird between them, just little looks and glances, but it bothered Buffy that Spike knew her better now, knew things about her that maybe even her friends didn't know, they'd shared so much during the time of that spell, more than she would like to recall...

"Whats up with you?" the bleached vamp complained, "You plan to kill things, so do I. No reason why we shouldn't keep each other company" he reasoned.

"I don't need your company, and I certainly don't want it" Buffy snapped, wondering how it were possible for him to get her so annoyed so fast. No-one could piss her off quite like Spike could. If she didn't know better she'd say that meant something!

"Y'know your problem Slayer?" he asked, not expecting an answer but getting one anyway.

"Starts with S, ends in pike?" she shot back at him, before spotting a figure in the distance and smiling, "Oh thank God. Demons" she gestured towards two nasty looking horned creatures to their left and Spike grinned as his features shifted into the visage of the demon within.

"Let's do this"

It was a sight to behold as the demons advanced and the two warriors fought back to back to fend off the attack. It wasn't long before Spike had snapped the neck of the demon he was fighting, and he turned to see the Slayer trying her best to kick ass but not doing as well as he would expect.

Spike had taken on Buffy himself, pre-chip naturally, and she was one hell of a fighter, he had to admit, made evident by the fact that she was the first Slayer to slip through his fingers this many times. That is why the blond vampire frowned so hard, with his human features now, as he watched the battle before him. For every punch and kick the Buffy landed the demon got in two or three and the girls nose was already running with blood.

As much fun as it was to just lean on the nearby tree and watch the Slayer get a good thrashing, Spike was intrigued, if not a little worried, that Buffy couldn't seem to cope with such a simple fight. As the demon threw her to the ground once more and it seemed she wasn't going to get up before it was too late, Spike leapt into action, bringing the demon down with a thump. Buffy hadn't been able to kill the thing but it was clear to the vampire that she'd softened him up a little at least as it didn't take long for him to be 'dispatched' along with his friend. Spike was unsure why he felt the need to white-knight it for the sake of a Buffy, but she was a Slayer and he figured it was just because he wanted the pleasure of taking her life with his own hands one day, when he finally got the stupid chip out of his head.

Standing up to his full height and breathing unnecessarily deeply, Spike turned to see Buffy only just now pulling herself to her feet. Her eyes took in the vampire that frowned at her and the two demons lying on the ground together in a pool of oozing green blood. She closed her eyes, took a couple of deep breaths, but found she couldn't keep it in any longer. She threw up in spectacular fashion, making Spike wrinkle his nose in distaste. He just looked away until he heard her stop heaving over a nearby gravestone, before turning back.

"Well, Slayer" he said with a smirk, "had no idea you were such a poncing light-weight these days"

"You're a pig, Spike" she shot back lamely, "Now, get lost" she began to storm off, though her legs didn't seem too prepared to take her weight. Spike followed her, still intrigued by the whole situation. Not only could Buffy not hold her own in a fight, but she was tossing her cookies at the sight of demon gore and her comebacks were just painfully pathetic. Something was wrong with her, and hey, if he couldn't beat on humans the least he could do was make their life hell in other ways - he owed that to his kind!

Suddenly he was aware that Buffy had stopped walking right in front of him, causing him to bump into her back.

"What is your deal tonight, luv?" he asked with a shake of his head as she turned around with a half angry, half confused look.

"I don't..." she began, "I think I..." her eyes slipped closed as her knees finally gave beneath her and she blacked out. Spike's arms shot out as he reacted on instinct and caught her before she hit the ground.

Unconscious, supported by nothing but his arms around her, Spike hated himself for the fleeting moment when he thought how beautiful she was, like a fallen angel. He wasn't blind of course, he always knew she was hot, but the way she looked now brought out the poet in him that he'd so like to bury and forget. Her golden hair, her perfect skin, her bright eyes...bright eyes? Hey, weren't they closed a minute ago?

"What the hell are you doing?!" the Slayer tried to yell, but her brain was only half in gear and it came out of more of a groaned complaint.

"Stopping you from bloody well hitting your head on soddin' rocks" he said grumpily, "ungrateful bint"

She wanted to punch him for that, really wanted to bring back her arm and smack him hard, maybe bust his nose, but Buffy found that every movement, no matter how slight, made another wave of nausea wash over her.

Throughout the day, actually throughout the past couple of weeks, she'd felt sick and wobbly on occasions, but she just put it down to the stress of juggling her Slayer duties with her new college life. Still, Buffy was not accustomed to feeling this amount of illness, the only times she could recall were years ago when she was a little kid, and those two times more recently when Giles was part of a plot to take her Slayer powers away, and then that one time she'd actually ended up in hospital...why was Spike still holding her? her mind suddenly screamed and she did her best to pull away and put her weight back on her own feet. She swayed slightly and swallowed back further sickness and found she could just about manage to walk away with a little dignity.

"Don't ever touch me again" she spat as she turned and exited the graveyard, leaving Spike behind. The vampire sighed and shook his head, that woman would be the death of him. The way things were going, she probably wouldn't even need a stake to do it.

A few metres away, Buffy stumbled out of the graveyard, steadying herself on the gateposts at the exit. She was glad Spike had decided not to follow her, but she hated that she'd had any reason to be close to him. With a deep breath she pulled herself up and made her way back to her dorm room. A good nights sleep was all she needed, maybe a lie-in since she didn't have classes too early tomorrow, that was all she needed she was sure.

One week later...

The ringing of the phone woke Buffy with a start, but all sitting up fast seemed to achieve was making her feel like she was going to throw up. Glancing across to Willow's bed she realised the red-head wasn't there, before the harsh ring of the phone reminded her why she was awake in the first place.

"Hello?" she said groggily, pulling the receiver to her ear and flopping back on her bed, the wire barely reaching the distance it was stretched across.

"Hey Buff" Xander's cheery voice greeted her ears, "You feelin' okay?" he checked, "You don't sound so great"

"You just woke me up is all" the Slayer complained, forcing her eyes to remain open and turning slightly to see the clock on the table.

"Buff, I know when friends spend time together their habits rub off on each other but even I get up before one on the afternoon!" the boy laughed as Buffy realised he was telling the truth, the numbers on the clock face finally coming into focus.

"I didn't realise" she said quietly, more to herself than to her friend. Deciding it didn't matter for the time being she asked Xander why he'd called.

"Oh, well, its about my evil dead 'house-guest'" he began, Buffy could almost hear the air-quotes, "he plans on getting his ass out of my place tonight but I have a shift at the pizza place, and since I don't trust the demon not to steal my stuff or just trash the place before he gets lost..."

"You want me to baby-sit the vamp?" Buffy guessed, with an unimpressed sigh. The past week, ever since that incident in the graveyard, she'd managed to avoid Spike most of the time. Now she was forced to spend a certain amount of her evening in his company, him giving her that self-satisfied smirk that he'd seen her weak for a moment, seen her let her guard down, helped her kill a demon that might have killed her if not for him.

"I know it's a lot to ask Buff, I mean you trying to juggle the college thing and the Slay-age, not to mention the new guy in your life..." Xander rambled on as Buffy thought briefly of Riley. He was sweet and kind and admittedly not bad looking, plus he knew about the demon-fighting, he worked for a government organisation that did almost exactly what she herself did, and that should have brought them closer together...but it didn't. She felt further from him because he'd lied and kept things from her, just like Angel had done. Of course she'd been just as secretive, but she felt she had the right - sacred destiny and all.

"Buff?" Xander prompted her for an answer for the third time and with a slight shake of her head the Slayer came back to the present.

"Oh yeah, Xan, sorry" she apologised, "I'll head over to yours as soon as the sun sets, okay?"

"Thanks Buffy" her friend grinned, "I owe you one"

They said their goodbyes and Buffy hung up the phone before flopping back amongst the bed clothes. Her hands landed across her stomach and she frowned, lifting the sheets and inspecting her body. Was she putting on weight? She frowned at the thought. She didn't really get fat or un-fit, one of the better parts of the Slayer deal. As Willow once said, she was naturally buff Buff!

With a shrug and a sigh, Buffy pulled herself out of bed and got dressed, forcing back further feelings of nausea as she checked her schedule and made her way towards her first afternoon class. She'd only missed one lecture that morning and she was pretty sure she could get some notes from a friend and sweet-talk the teacher...at least she hadn't missed Professor Walsh's Psychology class!

Buffy was fairly pleased with herself. She'd managed to get through her afternoon classes, do some extra studying, and make herself look pretty good before she headed over to Xander's place. The plan was to make sure Spike got out without taking Xand's stuff with him, or mindlessly trashing the place just for fun, then she was Bronze-bound for some quality time with her boyfriend. That sounded weird even in her own head. She and Riley had been getting close for a while now and she'd kissed him during that silence thing with the Gentleman. Since then there had been issues, especially when the truth came out about him being an Initiative commando and her being the Chosen One. But she still liked him and he still liked her and the more she thought about dumping him, the more petrified Buffy got. Did she want to be alone? Did she want to be the kind of girl who couldn't make a normal relationship work? Of course not, so she'd accepted what had happened and moved on.

Two nights ago, on her birthday, there had been some major kissage, on her bed. Obviously she'd been enjoying herself, Riley knew what he was doing, but a part of Buffy found herself comparing his kisses and touches with those of Angel, and a truly disturbing part of her brain reminded her how good it had felt to act that way with Spike just a couple of weeks ago under Willow's 'will be done' spell. Of course, Buffy hadn't actually gotten a choice about how far she went with her Riley because Willow had burst in and dragged them off to a surprise birthday bash, but she was pretty glad they hadn't gone too far just yet. She'd jumped head-first into her relationship with Angel and that had ended badly, then there was the thing with Parker...

Buffy shook her head of all her crazy mixed up thoughts as she arrived at the door to Xander's basement. She knocked once before entering the room to find Xander and Spike yelling at each other.

"That's my radio!" Xander bellowed as Spike held the offending item in his hands, "You're trying to steal my radio?!"

"Yeah, I'm evil" the British vamp replied, looking at the boy as if he were stupid, "What you expected me to not try and nick the half-decent stuff you've got?"

"No, he expected it" Buffy told him as she came in, taking the radio out of his hands as she walked past to stand by her friend, "That's why I'm here"

"Again Buff, I totally owe you one" the brunette gripped her shoulder in a friendly gesture as he pulled on his striped Pizza Palace shirt and left with a wave.

"Alone at last, eh Slayer?" the bleached blond leered, "Seems you've been avoiding me of late"

"I've always tried to avoid you Spike" she told him with a smile full of fake-sweetness, "Part of my plan for not regurgitating my meals" she told him nastily, though she realised her insult was all tied in to the truth. She'd come close to, or had actually thrown up, many times lately, with or without Spikes help!

"Fine, have it your way" the vampire shook his head as he grabbed his cigarettes and lighter from the table, shoving them into the pockets of his duster that hung on the back of the chair.

Buffy watched with disinterest as he checked the pockets through again and looked around the room as if he'd forgotten something - Buffy couldn't think of anything he might be leaving behind, he didn't have a whole lot to begin with.

Suddenly her thought process was interrupted by a bleeping sound and she frowned as she saw Spike head for the washing machine, his back to her.

"What the hell are you doing now?" she asked incredulously, stalking over to him and grabbing his arm to turn him around.

He scowled as she caught sight of the bottle of fabric softener in his hand.

"When it bleeps I put the stuff in, okay?" he snapped, doing just what he'd said, "What with me having the handicap and all and my only supply of blood coming from the Whelp, I didn't have much choice but to..." Spike's sentence tailed off as he noticed Buffy had her eyes closed and was leaning back against the wall, an unhealthy look on her face.

"You feeling alright, Slayer?" he asked with a frown, "Not gonna chuck again are you?" he checked with a distasteful shudder, he'd seen quite enough of her insides in the graveyard last week.

"I'm fine" she lied, the smell of the fabric softener making her stomach turn. It was strange, she realised since she usually loved that spring fresh fragranced stuff, just like her Mom always used, but right now it was really making her feel...she swallowed hard and lowered herself to the floor, head resting on her bent knees as she leant her back against the wall.

Spike wasn't entirely sure what was going on, but he didn't trust the Slayer right now. She was acting weird and he was practically helpless if she turned on him. Cautiously he recapped the bottle in his hand and put it down, gingerly walking over to Buffy and crouching down in front of her.

"Buffy?" he prompted a reaction from her but didn't seem get one, neither of them really paid attention to the fact he'd actually used her name for once, "You okay, luv?" he checked again, slightly surprised by the fact that it bothered him. He guessed he just didn't like the idea of her popping off of her own accord when he wanted to be the one to end her days, same as when that demon tried to take her down in the graveyard last week. Yeah, that had to be what it was.

"I'm fine, really" her voice was small when her head finally rose slightly and she tried to drag herself to her feet, still lying about how well she really felt. Spike backed up sharply as she got to her feet and stepped forward. He still wasn't entirely sure that this wasn't some kind of trap, a trick of some sort that ended with his getting decidedly dusty.

"Get out of my way, Spike" Buffy ordered weakly as she walked forward. With nowhere much to go in the cluttered basement and her wobbling from side-to-side as she moved, the vampire had no choice but to back up, eventually tripping on the edge of the table and landing in the chair he'd been sleeping in these passed few days.

Putting a hand to head, feeling suddenly more dizzy than she even had before, Buffy pitched forward and fell in a dead faint - right on top of Spike.

For a moment he considered pushing her off. He didn't want some filthy Slayer on him...but she was still a woman and despite the demon within he was still a man. She was warm and soft against him, and memories of being this close to her before flooded into his mind - the effects of Red's spell a couple of weeks back. Though he'd never admit it to anyone but himself, those few hours, believing he was in love and getting married, were the happiest he had ever known.

Coming back to the present, Spike carefully manoeuvred the Slayer on top of him so he could sit up, cradling her unconscious form on his lap. She looked so peaceful, he'd wager she didn't get a lot of quiet time being all Chosen and everything.

In the silence of the room he could hear just her even breathing and the constant thump of her beating heart. Daring to hold her a little tighter, just to feel that closeness again, he realised there was a third sound coming from inside of her. It was very faint and barely audible but with his vampire hearing, being so close to her, and having such quiet surroundings, meant Spike was able to hear this tiny sound, like a tapping at high speed. With a gasp he looked up at the Slayers face, wondering if she had any idea that two hearts beat within her. She was carrying a child.

To Be Continued...

A/N2 : Good idea? Bad idea? Please let me know what you think so far! :-)