Title: Under my Skin

Part: 1?

Author: Sara

Rating: Teen

Pairing: Derek/Casey

Summary: There are moments in everyone's life where the world changes forever. Casey knows that this is one of those moments. She's been having a lot of them lately.

There are moments in everyone's life where the world changes forever. It tilts on its axis and nothing will ever be the same again, no matter how hard you try to put things back to the way they were.

Casey knows that this is one of those moments.

She's been having a lot of them lately.

They're getting easier to identify. Casey's not sure whether or not that's a good thing.

She hasn't, however, been able to find any logical way to predict the changes that these moments will bring. It makes her feel uneasy and knots up her insides.

It's all that she can think about as she watches her mother pace back and forth across the warn carpet of Derek's dorm room as she sits inches away from him on the couch. She doesn't look at him or George, who's settled in the chair across from them. Although she's sure that his face is painted with concern, parallel of that to her mothers.

Instead, she pulls her knees to her chest and wraps herself tighter in the blanket around her shoulders. It's a vain attempt to hide the fact she was unable to retrieve her bra from wherever Derek had thrown in earlier. She was pretty sure it was somewhere between the couch and the make-shift kitchen table but she can't bring herself to look for it.

If anyone else had noticed it, they hadn't said so. Instead, a heavy silence filled the room which was only broken by the occasional muffled voice of Derek's roommate from outside the dorm's door. Casey had been able to pick up the words "step-sister" and "pervert" several times before she had finally begun to tune him out.

After what seemed like several hours, although it was probably no more than a few minutes, her mother finally turned to her with worry in her eyes and kneeled in front of her daughter.

"Casey, when did this all start?" her mother asks; her voice weak. The only other time Casey could remember her mother sounding this fragile was after her father left and she had been explaining to her how they were going to live with Grandma for awhile.

Casey closes her eyes and tilts her head back until it came in contact with the couch. She can feel Derek's hand as it slips under the blanket and brushes against her arm. It's calming, which is an effect that Derek rarely has on her. Normally his touch lights her on fire, whether with passion or rage depends on the moment.

She takes a deep breathe and ponders the question. Casey's not sure how to answer her mother, she and Derek had never really a defining moment in their relationship. Was it the day they first met, a week before the wedding, with Casey realizing a little too late the cute boy across the restaurant was soon to be her step-brother.

Could it have been the first real fight, their breathe becoming heavy as their bodies pressed up against each other in a battle to win the remote. She remembers that it had left her hot and sweaty with a strange sense of longing after her mother and George had pulled them apart.

Or was it the firs time they had put aside their difference and worked together, proving that they were stronger as a team than as opponents. Not that either of them would ever admit to it at the time.

Casey realized than that although they lacked a defining moment, she knew the instance that had triggered the transition from repressed sexual tension to the situation they were currently in.

"Michigan" Casey finally answered, finally looking over at Derek to gage his reaction. "It all started in Michigan."

xXx

It had been the summer after Derek and Casey graduated high school when George and Nora had suggested taking a family vacation. It was a result of the realization that come fall, their two oldest children would be moving an hour away to the University and that family time would be reserved only for summer vacation and holidays.

The first week of June they had packed up their bags and made the days drive to Mackinaw City, Michigan. Casey knew that the place was a tourist trap but her mother had visited it as a teenager and had always longed to go back.

She had slept most of the way there, her face pressed up against the cool glass of the window in the backseat. Derek had managed to keep Marti, who sat between the two of them, occupied for most of the trip and she was secretly thankful for that.

Derek had awoken her with a gentle shove as they began to cross the Mackinaw Bridge.

"Thought you might want to see this," he whispered softly in order to not wake up Marti, who had fallen asleep with her head in his lap.

The two had been on better terms with each other since the beginning of their senior year, when they had entered in a pseudo-friendship shortly after Derek began to date Emily. The less they fought with each other the smoother their respective relationships with Emily and Sam went.

They still bickered and fought around the house but even those, after three years of living together, had became more playful than malicious.

Despite the fact that the arrangement had made Casey's life less chaotic it had never felt right to her. It was like being caught in a thick fog, everything was dull and blurry. It paled in comparison to the vivid colors that her fights with Derek years earlier had made her see, not that she had understood at the time what that meant.

Casey had rationalized that there was comfort with consistently. She had known what to expect from Derek when they were at odds with each other.

She had hoped that after he broke up with Emily over Christmas vacation that things would go back to the way they were before.

They hadn't.

Even after she and Sam had ended their relationship a month earlier, something that hadn't upset Casey nearly as much as she had expected it to, the after effects of their truce lingered on.

"Thanks," she answered as she pulled herself out of her train of thought, turning her attention back to the large bridge that connected the two peninsulas of Michigan. The waves of the lake splashed violent below them as they drove the several miles across it.

The rest of the afternoon turned out to be more fun than she was expecting it to be. They had parked their car and walked around the city as they looked at all the little shops, eaten some of the best fudge that she had ever tasted and finished off the night at with dinner at Piggily Wiggly, a pig theme restaurant that Marti had loved.

"George, it's getting pretty late. I think it's time we called it a night," Nora suggested as the family poured back into their car.

They had driven around to the numerous hotels for the next hour, attempting to find one which still offered two empty rooms next to each other. Finally, George returned to the car with two hotel room cards in his hand.

"Finally," Derek groaned in response, stretching his arms above his head and yawning. "Can we sleep now?"

"We have to decide how we're going to split up first," Nora explained, leaning back to look at them.

"I want to stay with Smerek!" Marti declared, bouncing up and down in her seat.

"Sure, Smarti," Derek had replied, ruffling her hair with his hand.

"Well, that's the problem," George started, look over at his wife. "The one room has two queen beds but the other only has one king. It's the best we can do, unless you want to try a few more hotels."

"No!" everyone in the car had declared, the business of the day finally catching up with them. Casey wanted nothing more than to crawl into a comfy bed and fall asleep.

After twenty minutes of debating which combinations made the most sense, with Marti pouting whenever an option came up where she didn't stay in the same room as Derek, Casey had had enough. "Mom, why don't you take the two queen beds with George, Edwin and Lizzie. I can share with Marti and Derek."

"You sure?" her mother asked, her eyes drifting between them. "You two don't really, well, get along."

"It's only for two nights, I think we can handle it," Casey replied.

"Works for me," Derek agreed, as Marti bounced excitedly next to him.

"Then I guess it's decided," George declared, handing Derek the room key.

If Casey had known the chain of events her suggestion would put into play, she was sure she would have never breathed a word of it. But at the time, as she gathered her bags and followed Derek and Marti up the stairs, she could only feel relief at the notion of fluffy pillows and warm sheets awaiting her. Even if she did have to share with Derek.

xXx

There's chapter one of my fic. Please give me feedback, whether it's good or bad. Not to mention, the more feedback I get the more encouraged I'm going to be to write more sooner. I can be a slacker so all the encourage to write part two will help. I hope you guys liked it!