A/N: So this is my first attempt at a FanFiction that I am taking the plunge and uploading. Just a short one-shot AU. Hope you enjoy. Reviews and constructive criticism encouraged and appreciated. I love Once Upon a Time and all rights and reserves go to the creators Kitsis and Horowitz.

Summary: Emma and Killian have a big brother kid sister dynamic. They each have feelings for one another but believe those feelings are unrequited. Trapped in Dave's closet, those feelings become harder to suppress.

"I'm stuck in here with you. Therefore, I'm in hell." Killian let out a deep exasperated sigh. Stuck in his best mate's closet - with said best mate's kid sister, all while trying not to make noise that would alert his best mate of their presence - was proving more difficult than originally planned. Of course, being trapped in the closet in the first place was hardly part of the plan. The plan was simply to spend more time with his best mate's sister – Emma – all while remaining tactfully disinterested by avoiding giving any clues as to his interest in her.

"Oh don't give me that crap Jones. It's not your brother on the other side of the door that is currently making sounds of make-out pleasure. Besides, you guys ensured me he wouldn't be home for another hour. And on top of that, you failed to mention he'd be bringing Mary-Margaret with him!" Emma hissed while doing her best to give Killian the stink eye in the cramped dark closet.

"Drop it Swan! Do you want to give it away that we are trapped inside Dave's closet? And Robin did mention Dave would be bringing Mary-Margaret over, hence our current predicament. And what is that smell?" Killian wrinkled his nose in annoyance.

"David's gym bag… and his hamper. What's a matter Jones? Can't stomach the smell of your best friend's workout pants?"

"Bloody hell." Killian couldn't help his head from falling against the closet door, unintentionally causing a loud THUD to ring out.

"Did you hear that?" Mary-Margaret's petite voice spoke from the opposite side of the door, just as Killian and Emma let out a whispered and simultaneous "Shit!"

"Probably just one of the baseballs falling off the shelf in the closet. Don't worry we have the house to ourselves. The gang's all back at Granny's and I'm pretty sure Emma's at the library." Dave assured his girlfriend, bringing her attention back to him.

Inside the closet Emma let out an exasperated sigh. "Nice going Jones."

Killian pushed his tongue to the inside of his cheek and rolled his eyes, a sure sign of annoyance for Emma to witness if there was any light in the closet. "Forgive me Swan, but I had other plans for which I had wanted to spend my afternoon, rather than lay witness to Dave's make-out session."

"Well maybe you should have thought of that before getting us into this mess!" Emma stepped on Killian's foot to emphasize her point. He let out a mumbled "Oomph" which she attempted to stifle by placing her hand over Killian's mouth to silence his squeaks of pain.

** Flashback 1 hour earlier… **

The gang of oversized adolescent boys sat around Dave's living room, directly adjacent to the kitchen where Emma was pealing fruit.

"Oye! When is Dave getting back? He was supposed to be here half an hour ago." Robin, the sandy haired and bearded boy asked Emma.

"Don't know Hood, I'm not my brother's keeper. I thought that was Mary-Margaret's job…or Jones's. Now feet off the coffee table." Emma's steely look and tilt of her head as she was peeling an apple had Robin removing his feet off the table and gingerly placing his feet on the ground.

"Very funny lass. As you so eloquently put it, I am not in fact your dear brother's 'keeper'." Killian retorted as he came up behind Emma - his hand grazing across her abdomen just inside the personal space afforded by her raised elbow - and pilfered a slice of the apple she had just cut. Emma stilled at his sudden movement and tried to hide the creeping blush that was slowly spreading across her cheeks.

"Watch it Jones."

At Emma's blanket remark, Killian bit off a slice of the apple and winked at her. He took pleasure in the brief widening of Emma's too green eyes as he turned on his heel and walked backwards into the living room.

Killian loved getting under Emma's skin. Though she may be his best mate's sister, and though all their interactions since meeting all those years ago had been just that – keeping in-line with viewing Emma as a kid sister – it was becoming increasingly difficult to ignore the attraction he felt toward her. An attraction not conducive to their "annoying big brother to your annoying little sister" dynamic they had created years ago and maintained to this day. Every day Killian would tease Emma, ruffle her hair, steel her food, do all the things that annoying big brothers do to kid sisters. In return, Emma would stick her tongue out at Killian, bat his hand away, deliver a backhanded remark to him, and wrestle out of his ruffling of her hair.

Killian had assumed his growing attraction to Emma, as a young woman and not as a kid sister, was one-sided. But there was something in the way her body stiffened when he reached across for the slice of apple, something in the way her green eyes widened at his wink that gave him pause. For the past year, since Emma turned 17 and his attraction began to grow, Killian had been attempting to talk himself out of his attraction by convincing himself that nothing could ever or would ever happen between them. Emma is Dave's little sister, and by definition, off-limits. Also, he was four years older than her, how would that even be appropriate? Surely he had imagined the faint pink blush that colored Emma's cheeks as he walked away?

"Hang on a second guys, I just received a text from our dear old Dave." Robin informed the group, just as Killian sat on the couch and deliberately placed his feet on the coffee table in the hopes of receiving a scolding from the lovely Swan girl. "He says to scram and meet him later at Granny's. He's apparently bringing his lady love over in the next hour to do some 'studying'."

"Yeah. Studying. Why can't Nolan ever just be straight with us for once? He's blowing us off to make-out with his girl." Will voiced from his position on the floor, throwing a baseball in the air and catching it with his glove. "Oomph!"

A shoe landed on Will's stomach, causing the baseball in the air to also land on his stomach. "Watch it Scarlett. You know Dave, always the Prince Charming. Just because he doesn't give us details about his trysts, as you do, doesn't mean we should go blabbering about them for him." Robin stated as he yanked his shoe back from where it lay next to Will.

"Fine. But make-out fest or not, he owes us big time. He was supposed to help me fix up my bike this afternoon." Will said as he rubbed his bruised stomach.

"Right well you heard the man. Meet him at Granny's and get out of my house." Emma declared as she waltzed across the living room, plate of apples and cheese in her hand. "Some of us have to study," she continued as she batted both Killian's and Kristoff's hands away from her plate of study snacks.

"You sure you're studying too Emma? No plans with Neal this fine afternoon?" Will barked from the floor. "Oye!"

Two pillows hit Will square in the face. "Shut it Scarlet," Kristoff ordered from the sofa.

Turning his attention to Emma, Killian noticed her posture had gone rigid and a cold frown covered her face. "Forgive him, Emma. You know Will, too many hits to the head from a baseball during high school. You'd think he'd learn to not put his foot in his mouth, but well, never could get him to learn that if you piss off a pitcher enough times you're bound to get a ball to the head." At that, Emma turned her cold stare from Will to Killian. Her expression softened at Killian's joking, and she nodded her head towards him in silent thanks.

"Okay, well, see you guys later. Just make sure to clean up before leaving." Emma turned on her heel and left the living room to head upstairs to her bedroom. "Swan, wait." Killian's voice stopped her before she was halfway up the stairs.

"What?" She asked with an arch of her brow.

Her expectant expression gave Killian pause. Why the hell was he asking her to wait? Why the hell was he at a loss for words as his gazed locked with hers?

"Well?" Emma asked once again, a hint of annoyance in her voice.

Right. Annoyance. She has no idea you fancy her, Killian thought to himself. Best to keep up with pretenses. Killian straightened and arched his eyebrow as he swaggered up the steps towards Emma, a thumb laced through his belt loop, and spit out the first thing that came to his mind. "Might I have a look at Dave's room? He borrowed some class notes of mine that I'm needing to get back."

Emma looked over his shoulder as the gang of boys was exiting through her front door. She returned the wave goodbye of Robin's and then focused her attention back on the dark haired, dark bearded, blue eyed boy in front of her. Killian had always been like a second older brother to her, despite the crush Emma developed for him back when she was 11 and he was 14. Now, at 17, Emma still couldn't stave off her crush, even knowing that this 20-year-old man would never return her feelings. After all, her boyfriend Neal of two years had burned her only six months ago when she wouldn't put out. Why would Killian, a man who viewed her as a little sister, ever see her as anything else?

She knew her place in Killian's life, as his surrogate kid sister, and she feared when he would one day stop viewing her family as his own. The Nolan's had adopted Emma when she was 11, around the same time Killian came into her life as Dave's best friend. Though not an orphan himself, the Nolan's basically viewed Killian as an extension of the family, as an adopted son, since his parent's never seemed to be around. Despite Emma's crush, she never wanted to lose the companionship she shared with Killian. Yes, he was annoying. Yes, he aggravated her to no end and seemed to relish in it. His off-handed jokes, his stealing of her food, his behavior and mannerisms whenever a baseball game was on – especially the Pirates, seriously the fucking PIRATES – were ridiculous! But despite it all, he was the one person apart from her brother David that she could always count on. Whatever this attraction to him was, surely it was one-sided and would fade with time.

Emma blew air up at her bangs. "You don't need my permission, and you don't need me to show you the way." She shrugged her shoulders. His request was certainly out of the blue… and unusual. Killian knew he had unspoken permission to wander about the house as he wished, especially considering the guest room was essentially his.

"Many thanks Swan." Killian followed her up the stairs the rest of the way. As she turned to head in the direction of her room, he couldn't stop the request from falling from his lips. "Could you help me look for the notes Swan? You know your brother, bit of a pig sty his bedroom." He held his breath hoping Swan would acquiesce to his stupid request. Could she see through his charade? All he was wanting was a little more time with her before the days end. Best get back to pretenses before his feelings truly began to show.

Emma rolled her eyes. "How many times do I have to tell you my name is E-m-m-a. Or Nolan, or whatever nickname you can think of. But can you drop it with the Swan? That was years ago." Killian perked up at Emma's bristled and expected response. Ever since she attempted to rescue a duck six years ago, mistaking it for a Swan, Killian couldn't help but tag Emma with the nickname. Especially since Emma chased the poor duckling into the lake, fell in, and had to walk back home all muddied and dirtied.

"Whatever you say…Swan." Emma rolled her eyes and shoved him into the wall in response. "My apologies," Killian bowed his head in laughter and followed Emma the rest of the way into Dave's bedroom, "As you wish…Swan."

This time he was ready for Emma. He grabbed a hold of her outstretched arm and pinned her around so that her back was facing him. He could smell her scent, something a mix of almonds and cocoa, that he lost his train of thought for a minute.

What a precious minute to waist as Emma used the back of her leg to knee him in his groin, "Oomph!"

"You were saying Jones?" Emma turned on him and relished in Killian's display of rosy cheeks and bulging pupils. "Now do as you requested of me, and lets look for those damn notes. Honestly, you boys are attending the local community college, isn't it about time you guys started actually doing your work on a laptop or tablet? Sharing paper and pencil notes is a waist of time."

Killian shook off the kick to his crotch and cleared his throat of any remaining sounds of pain. "Some of us are a bit old fashioned Swan - watch it." Killian pointed a finger at Emma as she took up a baseball and attempted to look as if she was about to throw it at him. "Watch it darling, I believe my valuable assets can take only one beating per day." Emma cocked her eyebrow and set the baseball down on her brother's nightstand, next to the her plate of apples and cheese, and mumbled, "valuable indeed." Killian quirked his head up at her subtle response, but before he could make a suggestive retort, his attention turned toward the open bedroom door at the same time as Emma.

"What was that?" Killian asked. The sound of silly laughter and footsteps on the staircase was his only response, followed by his best mate's distinctive voice. "Let's go upstairs. I'm sure I can find a shirt small enough to fit you to replace the one with spilled hot sauce on it. And if you decide to keep the shirt and other items of clothing off in the meantime, well…"

At that, both Killian's and Emma's eyes bulged out of their sockets as the realization of what Dave was implying sunk in. Before either could think straight, they both made a beeline to the door opposite of, and incidentally farthest from, the bedroom's entrance. The last thing the pair saw just before they managed to shut the door was Mary-Margaret being walked backward, and bare backed, into Dave's bedroom.

** Present… **

Emma began to remove her hand from covering Killian's lips, only to admonish him in the process about keeping quiet once more.

Killian's gaze remained locked on Emma's. Even in the darkness of the closet, he could tell his eyes were boring into Emma's green irises.

"That's twice today Swan. Enough with the physical attacks yeah?" Emma nodded her head in agreement before allowing a "Sure" to escape from her lips. Killian tilted his head up as if pondering something, "Didn't you have a plate of apples and cheese with you?"

Emma smacked her head with the palm of her left hand. "Shit! I left them on Dave's nightstand. Do you think they'll notice?"

Killian smirked, "Not bloody likely from the sound of it. Pity. Could have used a good snack right about now."

"You seriously want a snack to go along with this show we are bearing witness too?" Emma asked half jokingly half incredulously.

"Course not. However, it has been a good few hours since I last ate, and that bite of apple from earlier only wetted my appetite. Oomph! Swan!"

Emma shook her head as she glided her back down the side of the door to sit cross-legged in the tiny closet. "Sorry, third time is the last time. Promise."

Killian slid down the door to sit next to her. Being taller than Emma, he couldn't cross his legs so he settled for bending them in front of him. "Apology accepted, but may I ask what I did to deserve a third smack-of-the-day?"

Emma leaned her head against the door and let out a laugh, "I thought you were making an innuendo. Or at least, making a joke about the current 'wet appetites' occurring beyond this door."

Killian turned to face Emma, eyebrow raised, "Now who's making innuendos and dirty references hmm?" Emma began to giggle beside him, her chest rising and falling with each stifled laugh. "Don't laugh Swan, that is your brother we are talking about." Now they were both laughing, and finding it increasingly harder to keep the laughter to whispers. Emma couldn't help the snort that escaped her nostrils, even as she turned her head to settle into Killian's neck to stifle the noise. Killian's laughter began to deepen and turned from whispered stifles to outright barreling chuckles deep from within his chest. This in turn caused another snort from Emma.

"What the hell?" Dave's voice carried from behind the door. More laughter and chuckles ensued from the closet. "Holy shit!"

Killian and Emma heard the pounding of Dave's feet before their brains could register that the door was being yanked open. Still in a fit of laughter, they fell with their backs hitting the floor, as the door no longer supported their weight. "Shit!"

While still laughing, Killian rolled onto his stomach and began to lift himself up push-up style onto his feet. "Sorry mate. Didn't mean to interrupt - " Emma, still laughing on the floor, looked up at Killian. He smiled down at her as he offered his arm to hoist her up. "Or witness," Emma finished for him.

Once they were both on their feet and the laughing subsided – for the most part – Emma and Killian shared a glance at each other before turning their attention back toward Dave. "We'll just be leaving then." Killian said to a dumbstruck Dave. They exited the room and shut the door behind them.

"What was that all about?" A blanket covered Mary-Margaret asked.

Dave turned his attention to the now closed bedroom door. He shook his head in wonderment, "I've no idea." Before heading to the door to lock it, the door sprung open and a light-footed Killian entered the room again.

Walking toward the nightstand as if he was a cat burglar afraid to loosen a floorboard, Killian made a grab for Emma's forgotten plate of apples and cheese. "Don't mind me, just needing to grab sustenance." Killian paused in the bedroom's entryway and turned back toward Dave and Mary-Margaret with a smirk and raised brow, "Unless you'll be requiring some after your tryst?" Dave slammed the door in his face.

Upon hearing the magic "click" of the lock, Killian turned on his heel and headed towards Emma's bedroom.

"Well, I'd say we gave them a right good scare of embarrassment. Here you go love." Killian placed the plate of snacks onto Emma's desk.

Emma, sitting in the chair next to her desk, was much more composed than she was mere minutes ago. She gave Killian a nod of thanks for the plate of snacks and looked toward her door. Killian nodded his head and made to make his leave.

"Killian?" His name on her lips stopped him in his tracks. He turned his head to look at her over his shoulder, but his body position still aimed to make an exit from the room. "Was it really hell? Being stuck in there…with me?" Emma asked with her head downcast, unable to meet his eyes.

Killian then turned his entire body to face Emma. He shook his head fervently. "No love, it wasn't hell." Emma raised her head from staring blankly at the floor but still wouldn't meet Killian's gaze, instead focusing on the poster above her bed. "Emma, look at me." She still didn't face him. "Love." That got her attention.

She turned her head and met kind blue eyes and a soft smile. The smile she fell in love with all those years ago as a child.

"Being with you is never hell." She allowed the ends of her lips to turn up in a short smile. He continued, "The situation was not ideal, but if happened upon again, well… There's no one else I'd wish to be trapped in a closet with to unintentionally witness the romantic frolicking of my best mate." Killian let out a small laugh and shook his head. He began to walk backward towards the entryway of her bedroom, all while keeping his gaze on her. "Perhaps until the next time, Swan."

Emma nodded her head in response. She rose to her feet and approached Killian, who paused in his tracks while his head turned up in a curious tilt. "Until next time, Jones." With that, Emma rose on her tiptoes and kissed him on the cheek. She allowed herself to linger for a minute, feeling the scruff of his beard and inhaling his scent.

She stepped back and reveled in the thought that maybe Killian saw her as something more than just his kid sister - if his expression was anything to go on. He swallowed and cleared his throat, eyes dancing from her green eyes to her pink lips and back up again, a smile – or maybe a smirk - spread across his face. Emma smirked back and gave him a gentle shove out of her bedroom's threshold. Killian caught her hand as it left his chest from where she shoved him. He entwined their fingers and brought her hand to his lips. He kissed her palm and lingered for a minute, all the while keeping his blue eyes locked with her green emeralds. Content, he released her hand and took another step back, "Until next time, Emma."