Author's Note: So this was something that popped into my head while having a Grey's Anatomy marathon with the besties in preparation for the new season's début. I've never done a Grey's Anatomy Fic, haven't hardly read any either, so this is completely new. I was searching around and I noticed that there aren't really very many OC stories for this show, so I decided to give it a go! Who knows how it'll turn out, this is all just for fun after all.

Pairing: Mark Sloan/OC
*No one try to hunt me down and kill me- I'm a big fan of Lexi and Mark as well as a big fan of wondering what would've happened if Meredith and Mark would've given it a shot during a single one of the numerous moments they shared full of sexual tension. I just thought this might be cool to try, that's all!

Rating: Fiction M- For language, mild violence/graphic descriptions (it is a medical show, so duh!), adult situations/themes, etc.

Updates: This story has been newly edited as of 11/17/2015! I've condensed the previously posted six chapters into three and combed through them for mistakes, plus added and flushed out some bits here and there. So take a gander if you like! From now on it will be all new content posted. Like my others, there won't be a set schedule for updates, but I'm hoping to keep up with them better between daily life thisandthat's!

*Warning!:This story obviously won't stick right on target with canon episodes since I'm introducing my own character, and there might be some OOC moments in respect to canon characters, but I hope that you all still enjoy! Should there be any specific trigger warnings, I'll post them in the note at the top of the chapter!

Feel free to follow, favorite, review, and what not! I love story feedback and suggestions, but please keep any flames or negativity to yourself! I covet constructive criticism, etc., but I do not accept bullying. Wouldn't want me to let loose a batch of interns with scalpels would you? ;)

Disclaimer: I do NOT own Grey's Anatomy (trust me, I'd change lots of things and many who died would still be kicking!), its characters, or any other copyrighted/trademarked material that may or may not be mentioned in this story. I DO own my original character, and any personal plot bunnies I let escape!

There's no such thing as a grown-up, especially in the surgical world
~Chapter One~

The irate beeping of my alarm clock woke me from a night's sleep that couldn't even be considered a full night given that it had only been about five hours since my head made contact with my pillow. I was immediately regretting the shots of tequila that I had downed with my sister the night before upon her urging…seriously regretting. I could still taste the bitterness of the alcohol coating my tongue, making it fuzzy and thick as my head pounded in protest to the early morning, my mind cloaked in a hazy fog that made figuring out exactly where I had woken up a serious complication.

"Michelle!" Izzie shouted through my door, slamming her open palm against it. "Get up, we've got pre-rounds!"

I groaned out something inaudible back to her, burrowing down beneath my comforter once more as I sought out the darkness the fluffy down could provide.

"Seriously Chelle, we've only got an hour and a half to be there! If you want coffee…" She trailed off teasingly.

The ex-model already knew she had won.

"Alright!" I hissed angrily, throwing off the covers. "I'm up!"

I laid still in my bed, listening attentively for her retreating footsteps in hopes that I might be able to pull a fast one and slip back beneath the covers once more but instead, I was greeted by another round of her palm slamming against the heavy wooden door.

"Isobel Stevens if you do not stop that right now, I am going to kill you!" I yelled, jumping out of bed and storming toward the door before throwing it wide open.

The perky blonde met me with a knowing smirk and a large mug full of coffee, the scent of my favorite brew wafting up in tiny steam wisps. Instantly any animosity I felt toward her dissipated as I reached out with grabby fingers to snag the mug, greedily taking sips and shuddering as the warmth radiated throughout my stomach.

"Oh God, I love you, I really do." I groaned, leaning against the door frame. "You always know what I need in the morning."

"That's what best friends are for." She quipped before turning away, though she glanced back over her shoulder again, fixing me with a stern expression. "Seriously though Chelle, hurry up."

"Yes mother." I snipped playfully back at her, sighing as I padded down the hallway toward my sister's room.

I easily jiggled the handle just right and snuck inside to find her…already awake. It wasn't really a good sign, she's never awake at this time, she usually always takes another thirty minutes and even then it can be a chore to pull the girl from her covers. I frowned as I approached the bed, taking in her vacant, unblinking stare at the ceiling. My sister was…a lot of things; it was really hard to explain. Dark and twisty inside, broken, damaged; sadly, they all come to mind when describing the issues we sometimes find ourselves plagued with. Even I struggled from time to time, though the desire to see my sister happy overpowered most of it. Our mother had really done a number on us by the time we fled the nest, with my sister coming out the lesser well-adjusted of us both.

"Mere?" I murmured quietly, slipping into the bed by her side and curling my toes against her legs.

She shuddered in response.

"I don't want to go to work today." She croaked out, the first round of words in the morning scraping through her unused vocal cords. "I especially don't want to go to work after seeing our mother."

Frowning, I stroked her hair back from her face, taking in the signs that pointed to a slight hangover like I had felt previously but that the coffee was quickly (and thankfully) diminishing. She grabbed onto my hand tightly and wound her nimble fingers through mine, something she only does when things are really bad, the darkness of her mind taking over. Considering everything she'd been through lately (her McDreamy turning out not to be so dreamy after all, the code black we experienced together, being trapped in a hospital with the guy she loved but couldn't have…and his wife), I wasn't really all that surprised.

"I can't stand seeing them together Michelle. It's just so…" She trailed off, completely lost for words.

"Shitty." I finished.

She arched a brow at me, a small smirk gracing her face before she nodded in agreement and sneakily snagged the coffee cup from my hand, prompting my indulgent smile.

"I know," I murmured, looking out the window at the still dark sky. "But we've just got to keep on going."

"Easy for you to say, you're all bright and bubbly most days…it's disgusting Michelle, really." She snipped, grinning as she sat up beside me.

I rolled my eyes and stole my own cup back, ignoring her protests about being the older sister and therefore being owed exclusive first-cup-of-coffee rights. "It was by five minutes Meredith, get over it."

"Still!" She shouted, throwing a pillow my way as I retreated to the door.

With a giggle and a sidestep to dodge the offending fluffiness, I turned back to peer at her through the early morning shadows. "See you at the hospital after you take care of the bill at Mom's?"

Her slight grimace and a quick nod was all the answer I needed. Wiggling my fingers at her as a goodbye, I disappeared down the hall, ignoring the sounds of George's embarrassed outcries at seeing me padding through the hall in my underwear and tank top with a smirk before slipping back into my room and private shower to steam away the night.

~.~.~

A few hours and one too many grumpy patients not appreciating their morning check-ins later, I sank heavily onto the bench of the Intern Locker-room next to my sister, gratefully accepting the tall cup of Starbucks coffee she had balanced on the seat that I was now occupying with a declaration of my love. I drank happily, already feeling a tad better from the evil morning as the blessed caffeine surged through my veins. Izzie had been on a nonstop happy train and I was about to scream at the top of my lungs; even I couldn't be that happy at six in the morning, no sane person should be that happy at such a time. But eight-thirty had officially rolled around and I had Starbucks in my hands…and a sister who had remained dead silent.

"Mere?" I asked, looking at her quizzically.

Nothing.

"Meredith?" I tried again, ditching the short nicknames we had established for each other when we were five.

Nothing still.

"Meredith freaking Grey!" I shouted, snapping my fingers in front of her face.

She startled and looked to me with wide, panic filled eyes. Instantly I was on alert, searching the room for the cause before opening my mouth to ask if McBastard, ahem-Derek Shepard, had once again said or done something to her. Before I could accomplish my task however, Cristina burst into the room in a frenzy of jackets and coffee cups, her lips twisted in an outraged scowl.

"You know, he's acting like I committed a crime!" She snapped, barreling through the crowd of other interns and toward us. "Like my apartment is full of stolen goods."

I winced a bit and yanked George from her path by the back of his scrubs so that he wouldn't be trampled in her mission to make it to her locker, before turning back toward her and looking at the girl with wide eyes, the wheels in my sleep-deprived mind slowly turning to figure out what she was talking about.

"He's acting like I kept my apartment to hide stolen goods so I could do illegal transplants for money!" She cried incredulously, throwing her hands in the air dramatically after popping open her locker.

My eyes narrowed; this was about Burke.

"Ah, I'll take it Project: Secret Apartment is officially a bust then?" I murmured quietly, still glancing at Meredith's still and silent form sitting next to me nervously.

Cristina snorted sarcastically and began stripping her coat and winter wear, shoving them violently into her locker that was right next to mine.

"Are you sure he's not just acting like you lied about moving in?" Meredith quipped, her tone serious.

My eyebrows arched high on my forehead as I quickly turned to her, mirroring Cristina's reaction almost identically. She never took the side of the guys in our lives when it came to mini-spats and disagreements, especially after the whole Derek and Addison McMarried debacle. It was simply unheard of, completely out of character. Cristina's dark eyes darted to mine in a silent interrogation and I shrugged helplessly, glancing back at my sister.

"Okay what's wrong with you?" She asked, staring at Meredith.

Meredith glared like a pouty child up at her and then at me, almost making me bust out laughing with the way her expression contorted her face into that of a two year-old throwing a tantrum…until her next words reached my ears.

"Our mommy is a filthy whore." She growled out.

I choked on my coffee, prompting Cristina wake from her shocked stance so that she could smack me on the back a few times as I coughed and sputtered. Meredith handed me a napkin like she knew it was coming, which she probably did, and I wiped at my mouth before turning my bewildered gaze to her frowning one.

"What?!" I exclaimed, practically shrieking in the process.

Silence settled on our row of lockers in the room as others turned to look at us, Bailey's interns once more causing a scene, and Meredith shushed me before smacking me on the leg quickly in reprimand. I narrowed my eyes, glaring irritably at her in response.

"Well, it would've helped if you had given me a heads up!" I hissed, gesturing wildly with my free hand. "How do you-"

But then I was cut off by Residents coming to claim their interns, the crowd dispersing through the hospital hallways. Our rounds with our current Attending babysitters were starting and Meredith motioned to me in a way that explained she would tell me more about the situation later. I huffed out a sigh of both annoyance and pure confusion as I rubbed my temples, sucking down as much of the brand name coffee as I could between the bench and the doorway before I had to toss the cup into the trash bin as I passed it by, my sister once more at my side.

Another shift, ready to begin.

~.~.~

I ignored the group antics and bickering as we made our way through the halls before filtering into a patient's room behind Burke, one of our morning pre-rounders. I ignored Izzie and Alex's obvious sexual tension, her worried questions about rather or not I was alright, the sound of my sister delivering the patient's chart to Burke, everything. All I could concentrate on was the pouring Seattle rain outside as it streaked down the window in tiny rivers of water. Oh, and the fact that my mother, who had basically wrecked the home-lives and childhoods of her twin daughters, was an official home wrecker.

An adulterous wife.

A filthy whore.

"Explains a lot, actually..." I snipped to myself, worrying my bottom lip between my teeth.

I continued to ignore my surroundings as the morning moved along; the patient's words, Burke's questions, all of it- even as we filtered back out of the room and made our way in a small group down the hall, only to find Dr. Bailey waiting there, her new baby snuggled tight in her arms. She was talking, asking about the Code Black that Meredith and I had been caught up in; not that much of the hospital staff was all that surprised, if anyone would end up caught with a bomb in a body cavity and stubborn sister who refused to leave, it was Bailey's group of interns. Scenes still flashed back and played on the backs of my eyelids at night, hence the fitful sleep.

"Grey? Michelle Grey!" Bailey's voice ripped through my mind and my head snapped up, nearly leaving me with a crick in my neck, to find her stern but concerned eyes resting on me.

"Where did everyone…?" I trailed off in my questions once I looked up to find my fellow interns, and sister, missing.

"If you weren't off floating somewhere in space, you'd know they've moved on down the hall to Dr. Shepard's Craniodiaphyseal Dysplasia case." She murmured, rocking the newborn in her arms as her tone took on a more concerned note. "What's going on with you, Grey?"

I bit into my lip and sucked in an unsteady breath, shaking my head quickly. "It's nothing, just some news that I'm less than thrilled to receive."

Bailey looked at me sharply. "Are you…alright?"

I stared at her blankly for a moment before gasping, stumbling over my words to reassure her once I had figured out how my response had come across.

"Yes! Yes, absolutely. I just found out some things about my...mother...that I wish I hadn't, that's all." I gave a small shrug, trying not to act like a petulant child with my hurt feelings.

Bailey nodded once and looked down at the baby boy she held protectively to her chest before looking back at me.

"You know Michelle, as mother's we aren't perfect. I'm more than aware that you and Meredith had an even lesser version of perfection than most, but I'd like to think that there is a reason for everything. In the end, the shortcomings of your mother will only push you to do things differently yourself."

As she spoke I stared at her, sensing her concern and worry when usually I thought she almost couldn't stand us, especially when she'd learned that Meredith had been sleeping with one of our Attending's and I knew all about it, keeping it a secret from her as my Resident. Even though I wasn't actually at any fault for the decisions made by the two of them, I was Meredith's twin sister and therefore I was partially liable after being less than forthcoming. But her Bailey stood, cradling her newborn son as a new mother and doing her best to reassure me about mine. I smiled shyly and, on a whim, gave her a quick hug that she barely had the time to partially return, looking more than a little shocked.

"Thank you Dr. Bailey, for talking to me." I murmured before smiling and tickling the baby under his chin, "I really appreciate it."

She made one of those little noises she always did as I flashed her a bright smile and quickly disappeared down the hallway, giving her a small wave as I did so.

Finding my group wouldn't be impossible to do, I could easily look up the board or chart numbers and rejoin them. But the mere idea of seeing Derek Shepard flirt with and give my sister puppy dog eyes while he still went home to his wife every night, thus breaking Meredith's heart all over again, was simply something I couldn't handle at the moment, regardless of Bailey's advice and wisdom. So I quickly stationed myself at the nurse's station out front instead, waiting for them to come back around.

Meredith would find me, she always did.

~.~.~

My eyes scanned over the patients chart, taking the time to do some rereading over the condition of the man I had just left, learning what was wrong with him since I had completely zoned out and not heard a single thing that had been presented at the time, when her voice filled my ear to the left of me.

"There you are!"

Meredith grinned as she approached my side, jostling me out of the way of the computer screen with her hip and setting down charts in front of me as she logged on. "Where'd you disappear to anyway? On call room with a boytoy?"

Her ridiculous eyebrow-wiggling nearly made be burst out laughing.

"No," I pouted, then rolled my eyes as I leaned against the counter. "I wish. I totally spaced out after your mommy comment, actually. Bailey had to snap me out of it and then she talked to me for a while. Once I finished with her I just came here, I knew you would be coming around. Besides, I couldn't stand to look at McBastard this morning, much less listen to him."

She frowned at me, almost disapprovingly. "Don't you think that's a little harsh?"

I gaped at her, my mouth hanging open just the slightest as I stared. "Please tell me you're kidding, Mere."

"Fine, I'm kidding." She grumbled.

My eyes narrowed dangerously as I watched her, knowing she wasn't kidding, not even a little bit despite all that he had done. My hands fisted at my hips and I sucked in a deep breath, preparing myself for another session of why Derek Shepard would qualify as 'Douchebag of the Year', but my words caught in my throat. Suddenly, a long and thick leather-clad arm stretched out right in front of me while remaining between Meredith and I, pointing to the computer screen I had just been staring at and the one my sister now was, as a deep voice filled my senses.

"Invasive non-small cell with a history of C.O.P.D?" The stranger murmured, arching a finely trimmed eyebrow in question. "Guy's pretty much a goner huh?"

My eyes traveled up the arm slowly as a smirk bloomed across my lips, finding a firm chest, large shoulders, and an extremely ruggedly handsome man towering above the two of us where we stood. Words literally left my brain, every single last one of them, as my breathing hitched and I worked to settle my reaction.

Something he seemed to already know about, judging by the smirk that dawned his lips.

"Sensitivity- I like that in a stranger." Meredith quipped sarcastically.

Pulling my eyes away from him, I looked over at her and grinned at the dry humor; more than glad that her words had broken me out of the second or third mindless trance of the day, though this time it was due to the boiling hotness that stood in front of us rather than confusion and anger. The man's eyes darted between us quickly as we watched him, slowly widening some.

Grinning even more, I arched an eybrow.

I knew exactly what he could see; I was used to the reaction from guys, especially with the amount of bars my sister frequented.

We looked extremely similar, almost identical in so many ways but vastly different in others, giving us our fraternal twin status. Where her hair took on a more brunette hue sometimes, mine leaned more toward the blonde with golden-caramel lowlights sprinkled throughout it. Her eyes were a bright but stormy blue-green while mine were a hazel-green. We had similar builds to each other, similar bodies, but the features of our faces were definitely different, yet similar enough to throw someone off at first glance.

And start up the constant reel of dirty fantasies in just about any man's brain.

"Are you new here?" I asked, grinning when Meredith's eyes darted to me, a knowing look crossing her features.

"Visiting." He supplied quickly, tucking his hands away in his pockets as he eyed me before looking up to the skylights in mock confusion. "Confounded by all the rain, and it's only my first day in town."

Meredith shook her head a little and latched onto my sleeve, pulling me with her as she moved down the counter some. She knew I was already intrigued, probably more so than I should be. He was right up my ally of men I brought home, the typical bad-boy type. Tall, dark, ruggedly handsome and dressed in leather…mancandy at its finest.

"You get used to it." I murmured in reassurance, following after my sister, though I did so stubbornly since I refused to quit speaking to the guy.

"Makes me want to stay in bed all day." He added, stepping after us determinedly.

I sighed softly as Meredith looked at me disapprovingly from behind her chart. I turned from her though, letting my eyes wander over him as my tongue darted out to wet my lips, prompting his smirk to grow wider as he watched me take him in before he did the same to me. I could practically feel his eyes move over my body.

"We just met, and already you're talking about bed." Meredith snipped. "Not very subtle."

Rolling my eyes in response to the abrasive retorts, I nudged her with my hip playfully; all while our newly formed trio remained completely oblivious to McBastard's slow and shocked form rising from the conference table through the blinds of the meeting room directly behind the nurse's station and Addison's frozen stance about twenty feet from us.

"Subtle's never really been my strong suit." He countered, turning his grin on her.

I waited for the moment to come; it wouldn't be long before he had her grinning just as he had me. Even broken-hearted Meredith wouldn't be immune to those charming smiles and darkly handsome looks. It just wasn't possible. Sure enough, just as I expected, I saw the grin slowly start to creep over her features and a slight giggle passed through my lips, earning a wider grin from him and a tiny glare from her as she turned back to charting and I watched him look at us from her right side.

"So…" He said, his eyes flitting between the two of us quickly. "Do either of you ever go out with coworkers?"

Meredith sucked in a gust of air and I snickered quietly, flipping my hair back over my shoulder and out of my eyes as I answered for her, since she seemed to be incapable.

"Due to recent events," I murmured, my eyes darting to hers before meeting his again. "We're now making it a rule not to."

"Then I am so glad I don't work here." He murmured, shaking his head as his grin remained in place.

My brow arched and I leaned against the nurse's counter, crossing my arms over my chest, meeting his eyes boldly as I tried to contain the girlish smile and giggle that demanded to be released.

"I'm sorry, are you hitting on one of us…in a hospital?"

"Her, you…maybe even both of you," He proposed seductively, his tone like silk and his eyes glinting playfully as he threw a wink my way. "Would that be so wrong?"

The sound of his voice, it literally set off butterflies in my stomach, the fluttery feeling taking over my body. It was as if I were fifteen again, and the clenching of muscles and warmth radiating through my lower body had me swallowing quickly as I worked to feign normalcy.

He didn't buy it.

My sister's grin won out and she stuck her hand forward, introducing herself smoothly. He continued to grin as his eyes moved over her and then to me, obviously waiting for my own introduction as well. I smirked a little, giving his hand an inquisitive look, then finally stuck my own hand forth into his; holding back a sigh when his large and warm one completely enclosed mine, his fingers stroking themselves smoothly over my palm as he did.

"Mich-" I started, but was suddenly interrupted.

By a fist.

A freaking fist flying unchecked through the air from over my shoulder came out of absolutely nowhere and connected with our new friend's jaw. The aftermath was almost comical, in a way.

Since my hand was gripped so tightly in his I was yanked closer to him after he took the hit, causing the backwards momentum of the fist as it retracted from the stranger's face to connect squarely with my temple. I hissed in a sharp gasp of pain, instantly squeezing my eyes shut, and then I was pulled forward by mystery man's hand as he unceremoniously fell to the cool tile floor. Luckily for me, he realized what had happened and turned his body and arm in such a way where I connected with only his firm chest and toned abdomen instead of the hard tile.

"Oh Jesus." I moaned softly, prompting a small but painful chuckle from underneath me as the man's hands tightened on my hips some.

A sharp thrill went through me, provoking a shudder that I will deny to this day.

"What the hell was that!" I heard Meredith shout above me.

"That was Mark."

I groaned again, recognizing the voice of who appeared to be the assailant responsible for my now compromising position sprawled out on top of our mystery man, who was apparently named Mark, in the middle of my workplace. It had yet to dawn on me though that the aforementioned Mark was the same Mark that Meredith had told me about after Derek finally explained the whole situation involving leaving his wife and moving to Seattle to my sister after the redhead had shown up in our rainy city.

Derek…of course.

It was quickly all becoming clear.

My eyes blinked lazily as I felt something thick and warm beginning to snake its way down my cheek and neck before the man beneath me moved a single hand from my waistline to my head, ghosting his fingers over my skin until he hit a sensitive spot. I hissed in pain, my eyes springing open immediately to find his striking bluish-gray ones staring up at me in concern.

"Christ Derek, you hit the girl." Mark muttered, turning my head gently to the side.

A low moan of pain escaped my lips again, completely unwillingly. I gritted my teeth and sucked in a breath, refusing to show weakness in front of the newly formed crowd of my coworkers...again.

"What?!" Meredith's outraged shout echoed through my ears, making me wince for reasons both to do with my head and those around us.

"How bad?" I murmured lowly, looking down at him again.

"Pretty bad." He grimaced as I winced slightly in pain when he touched a sore spot. "You're going to need stitches and an x-ray probably."

"Oh Chelle, I'm so sorry-" Derek started, stepping into my line of vision.

Meredith seethed, her voice turning deadly as she dropped down beside me. "Don't you even dare-"

"Would someone like to tell me what in the hell is going on?!"

The loud, obviously irritated voice roared out from somewhere behind us before the figure stomped toward us. We all froze at almost the same time, our eyes widening as we looked up sheepishly to find Dr. Webber, Chief of Surgery at Seattle Grace Hospital...and our surrogate father...thoroughly pissed off.