Derek:

He'd stopped tickling her and their faces were inches apart. All of his thoughts were Casey, Casey, Casey; her hair, her laugh, her smile, her smell. He forgot where he was, who they were now. "Sam asked me out." Casey blurted looking panicked. Derek backed up and suddenly there was too much space between them. He was back on the bed and she'd rolled back a little in her desk chair.

Derek felt his chest tighten and he snorted derisively. "I'm sure it was out of pity." He felt panicked but he kept the cool look on his face. Now he remembered where he was. The house that they lived in, together; the house that they shared with their siblings and their now married parents. He though her face fell a little. She was crushing on Sam! He felt the air rush out of his chest like the first time in hockey when he'd been knocked flat on his back. "Well, I'm sure the two of you will have much to talk about." and he slid off of her bed heading for the door.

"Derek…" She started and he glanced at her over her shoulder.

"No, no. Date my best friend. If you don't find it weird, I don't find it weird. I'm sure it won't last long. He's cool and hangs out with me. And you, you're well… Klutzilla." He smirked heading to his room to the sound of his name split in two.

"Der-ek!"

The next day when he saw Sam, it was the same thing. "I asked Casey out." Derek rolled his eyes.

"Yeah, I know. She told me yesterday."

The shaggy blonde nodded his head, as if he already knew this information. "I was really worried man." And at this Derek perked up a bit, maybe she'd turned him down? If anyone asked he'd never admit to the feeling of guilt twisting in his stomach for wanting his best friend to get rejected. "She never really said anything when I first asked, and I thought maybe I misinterpreted everything… but she called me late last night and agreed." Sam closed his locker happily, following Derek to their homeroom.

Of course it had been last night after he'd insisted that it wasn't a big deal and that Sam wasn't really all that interested in her. Maybe she was doing it just to prove a point because that was about how half of their relationship worked. Maybe she just wanted to prove that Sam was really into her and it really wouldn't last all that long.

But then what? She would come back to him and they'd what? He'd been acting like he'd never met her before ever since their parents met. If Casey even looked like she was going to bring up the summer he'd do or say something to piss her off. Even if she hadn't changed her view back to that of him being a womanizer, it's not like anything could happen between the two of them. His dad married to her mom? Why was he wasting time thinking about her, about this? They'd talked for a few months and sure, he'd loved her but it was an easy thing to get over.

Right?

Casey:

So, she'd said she'd go out with Sam. Why not? He was sweet and kind and seemed to really like her. She could find herself liking him very much…

That was exactly the problem. She kept thinking things like I could learn to really like him which was really unfair to him but what was she supposed to do with the person she loved pretending like she was nothing more than his annoying step-sister. Like everything that happened this summer was, as she'd feared, nothing but a lie. During class and in the hall she wrapped her arms around herself as if it would keep her heart from breaking, as if it could keep the physical pain in her chest at bay.

Her date with Sam went really well and in short time they were an established couple at the school. Derek went on several dates with several different women. Pig. She and Sam hung out every weekend. She ran into Derek making out with someone different, it seemed like everywhere she went. Sam liked to hold her hand. Derek pulled pranks on her. She was yelling at Derek. He was laughing at her. It didn't matter that Sam's presence was constant and sweet… her thoughts were always on Derek. She was either irritated at a prank, worked up in a yelling match with him, thinking of ways to retaliate, wondering why he pretended they had never met, trying to ease the hurt that came from loving him.

Her first kiss with Sam was gentle and sweet. She felt nothing. She'd been feeling nothing more than friendship for Sam for a while now, but they continued to go out. It was completely unfair to him and completely unlike her but she really did want to feel something for him. The problem was he was too compliant… not enough, well not enough Derek if she was being honest with herself. Derek made her blood boil and unnerved her but he made her feel passionate and he had a way to get under her skin and stay in her head all day. Sam was kind and sweet but he didn't ignite passion in her, he didn't argue with her. There was just… nothing there.

So when he kissed her and her thoughts were on what she needed to do for homework—a thing Derek would scoff at and tell her was probably a keener thing, a her thing and not a Sam problem—she thought about breaking it off then. Then there was Derek poking his head out the door interrupting them mid-kiss. "Sammy. Babe raider." And there was the competitive part of her that wanted to prove to Derek that she wasn't stuck on him and that her and Sam were going to last longer than he thought.

He wasn't the only one who could move on. So she slipped her thumbs through Sam's belt loops and pulled him to her so they could kiss a while longer on the front porch. Naturally, though, Derek had to ruin it by clearing his throat until they broke apart and Sam went inside.

Derek shut the door behind them leaving Casey standing alone outside but that suited her just fine because she really didn't want to risk either of them seeing her cry.

Still, it was all a waste because a few weeks later Sam was breaking up with her because she was far too invested in Derek's date that night rather than theirs, as if dressing up in a blonde wig and spying on your step-brother's date wasn't a totally natural thing to do. So, he felt ignored like she spent too much time focused on Derek and they ended things.

Really, that suited her fine, too because the lack of passion between them was really starting to bore her. What she was more worried about was the fact that her disguise was not clever enough and Derek discovered her spying which just made her seem pathetic.

What was more worrisome was that her feeling of love toward Derek Venturi had not lessened in the slightest.

Things went on between them in pretty much the same fashion. Derek pranked her. They yelled and insulted. He dated girl after girl and she continued to be a serial monogamist which really meant she had no other relationships after Sam for the rest of the school year. The days on which Derek did nothing to her were the worst because it meant she wasn't on his mind. The days when he went out of his way to prank her or insult her were the best because it at least meant he was thinking about her.

Yes, she's very aware of the fact that she's very screwed up. It's his fault, not hers.

Then again… When he discovered their situation he moved right on while she was left hung up on a guy who cared nothing for her.

The first day of summer Beth showed up at her front door with an overnight bag and a bright smile. "I thought I'd come visit you, meet your new family…" she leaned in and whispered, "Give you some cheering up." Casey stared blankly at her best friend from when she was nowhere near this messed up in the head. Beth rolled her eyes, "Your mom said that your step-brother gives you hell and you recently had a break up and you needed some, well, me-time." She barely managed to choke back a sob before Beth had dropped her bag and pulled Casey in for a hug. "I figured something was going on when we stopped talking, but there wasn't a lot I could do if you weren't ready to talk about but it kept going on and well, here I am." Casey nodded into her friend's shoulder and then dragged her upstairs.

Thankfully her eyes were still dry because then there was Derek bounding down the stairs, having just woken up. His eyes still looked bleary, his hair still properly messy rather than stylized messy. He brushed past her to the kitchen, but she was sure if he'd seen her crying he would have become dramatic about it.

She didn't dare look at Beth until they were safely in her room. She crawled onto her bed, leaning against the headboard hugging her legs to her chest. Her guest gently closed the door and took her seat beside Casey.

"Oh." And really that's all she needed to say, because suddenly everything was very clear to the blonde about everything that was going on internally with Casey.

"Yeah."

"Ouch."

Again, "Yeah."

Then it was all spilling out. Everything from the day of the rehearsal dinner when she met her new step-family to hoping that when she told Derek that Sam had asked her out that he might finally acknowledge everything because he really looked like he might kiss her, to dating Sam because she was so, so screwed up.

There was a lot of crying and a lot of hugging but it felt really good to get it all off her chest.

"Are you sure he's over you?" Beth asked, looking sympathetic. Casey snorted—a bad habit she'd picked up from the boy on the other side of the wall.

"You would not believe the number of girls he's been on dates with this year. It's a wonder there's any in the school who haven't been out with him. Beth made a small noise in the back of her throat that was very non-committal. Casey sighed, "Well, now that you know everything… what's been going on with you?" And she could really focus on her best friend feeling so much lighter for having spilled her troubles to someone who held no judgement about it all.