A/N: I'm sorry if this chapter seemed a little rushed. It didn't flow exactly how I wanted it, but it turned into something okay. I realize Derek has been quite OOC in this fic, but I'm not exactly the writers of LWD, or Michael Seater, am I? I'm trying my hardest!

Also as a heads up: I've officially increased the rating of this story from K+ to T, for mild innuendo.

I do not own Life with Derek, nor any of the characters affiliated.

Everything made sense. This was meant to happen.

Derek couldn't believe it was happening. Just ten minutes ago, he didn't even think he had a chance in hell with Casey. Now, she was holding tight to him, letting him trace his kisses along her jaw, landing on her neck, nibbling her ear. He could feel her chest rising and falling with laboured breaths when his fingers explored territory under the hem of her shirt, his hands meeting her skin along her waist, finding their way to the small of her back. Her skin was so smooth. He could feel her body tense a bit when he hands tentatively massaged her back, and she breathed his name

He smiled. That was hot.

"Let's talk about this," she said shakily. It was just like her to try and control the situation.

"How about we talk later," he responded, blowing in her ear. Her body weakened with the sensation, but then she quickly pulled her fingers from his hair and pushed against his chest, wedging some distance between their bodies.

Derek grumbled, but obeyed, and removed his hands from around her waist, letting them linger against her stomach for a moment before he dropped them to his sides. "Okay, fine. Let's talk," he acknowledged, his hands making their way into his pockets.

"Derek, you don't have to sound so upset."

He didn't respond to that. His head tilted backward, and he propped it against the door.

Casey exhaled unhappily, and then muttered, "we can't do this."

He winced, closing his eyes. He brought a hand to his face and pinched the bridge of his nose. "Why not?" he fought, challenging her.

She tilted her head. "You know why not."

"Because of our parents?" His eyebrows knit closely together, and his tone was full of disbelief. "Come on, Case. Give me a break."

Her expression was incredulous, and Derek felt remorseful that she was struggling so much with their budding relationship. "This would completely devastate them!"

"Isn't that the point?"

Her eyes quickly darted away from his. "Yes, I know it is, but it's supposed to be fake. This wasn't supposed to be real. If they found out we were actually…" her voice trailed, like she couldn't bring herself from saying it.

"They'd get over it." Derek clenched his jaw. There was no way in hell he was going to come this close to being with Casey for her to just build another barrier between them. He had waited so long already, and he wasn't letting this opportunity slip through his fingers. He knew the chance would never come again once Casey made up her mind to distance herself from him. He could be pretty stubborn, but Casey definitely took the crown.

She shook her head. "It's not that simple," she breathed. "We can't just think about ourselves. We can't just act on all of our feelings."

"So you do have feelings for me," Derek interjected, catching the subtlety.

"That's not the point, and you know it. We can't be selfish about this."

This whole situation made him want to punch something. How could she say this moments after she threw herself at him? It wasn't fair. "Casey," he started, making sure his voice sounded much more calm than he felt. "When is the last time you actually did something crazy that you really wanted? Something for yourself, not caring about what the family will think?"

Her eyes went low. "Derek -"

"No, Casey. Do you really think that Nora thought about us when she left?"

Casey frowned. "It was you and me who suggested it."

"Well, I didn't really mean it. Did you?"

Her voice caught. "No."

"So do you think Nora was considering the family when she put the offer in on that apartment?" He stared at her, daring for her to argue that point. "If she can act selfishly for herself and put us aside, then we can, too."

Casey's eyes closed slowly, and she breathed deeply. She didn't respond to Derek's argument, thinking methodically.

Silently, Derek took a step closer to her until he could reach out and grab both her hands, holding them loosely between their bodies. In a whisper, he said, "look me in the eye and tell me you don't want this to happen."

Casey's eye's opened, but she didn't make eye contact, like he asked her to do. "It's not that simple," she repeated.

Was that the only explanation she could come up with? "Yes it is, Case." He let go of one of her hands, and then brought it up to her chin to guide her head up to face him. "Family out of the picture. Yes or no. Do you want this to happen?"

Her lips parted, her eyes glossy with a tear that threatened to fall, but Derek didn't shy away this time. This needed to happen, and obviously tears would be a part of it. "Of course I do," she breathed.

He tried to stop himself from smiling, but couldn't help letting it show a little. He was glad he did, because it made Casey break into a momentary grin, although it was short lived.

Before he did anything, he whispered," I'm willing to give this a shot, despite the family. But I can't really do it alone."

She let out a small, sad laugh.

"So what do you say? Are you going to be selfish with me, or what?" He studied her face, trying to unlock what was going on in her head.

Her mouth opened, but what came out of her mouth wasn't anything he had expected to hear her say.

"Marti."

That simple word disarmed him. He hadn't prepared anything for this, and he didn't understand why Casey was bringing up the youngest Venturi.

"...what about Marti?" he asked.

She visibly swallowed. "I'm concerned about what Marti's whole perception of this will be. She was so young when our parents got married, and she's become a vital part of the family. She's not just a Venturi anymore, Derek - she's a true McDonald sister, too. It's just… she might not understand how you and I aren't really related, while she's as much my sister as she is yours."

Derek bit his lip. How could this not have crossed his mind before? Marti was so impressionable. She looked up to Casey just as much as she looked up to him. Their actions would have certain ramifications on how his nine-year-old sister was to be shaped. If he and Casey screwed up, Marti could end up as one monumentally confused teenager, and Derek definitely didn't want that on his conscience.

He let go of Casey's hand and hastily ran his fingers through his hair. "You're right," he agreed. He cared so much for Casey and wanted to be with her, but he loved Marti, too - more than his own life - and he wasn't willing to decide what was more important. "But is she the only reason you have reservations about us?" He let Casey turn her body slightly away from him, and she rested her hands on the edge of the basketball bin. She didn't respond for a while, and every time she went to say something, it was like she chickened out.

Dejected, Derek cleared his throat, but to no avail. "I suppose you don't want to continue with this whole dating plan, then," he said.

Hastily, Casey's eyes widened. "No!" she blurted, and then realized how loud the outburst had been. She smiled apologetically and raised her shoulders, like she was trying to shrink. "I mean, yes," she recovered, and then scrunched up her nose, which Derek found extremely cute. "I do want to continue. I want our parents back together, but… I want everyone else on board."

"Hmm?"

She stepped closer. "I'd feel better about us - I mean, the plan - if Marti and Edwin and Lizzie were in on it."

Derek liked the fact that she was - again - standing so close to him that their torsos were brushing against each other, teasing him with every movement.

He smirked. "I guess I should have told you, but Ed already knows."

"He does?"

"I told him everything last night." Derek shrugged. It was no big deal. And she said it herself; she wanted the sibs to know.

"Everything?"

"Everything."

"I see…" her eyes narrowed.

He rolled his eyes. "Relax. He won't tell Dad. He's on our side, remember?"

She looked at him skeptically, and he knew she was wondering just how much Edwin knew, and how much Derek would tell him about what had just happened. But she didn't have to worry. Derek knew this moment alone with her - full of confessions and passion - was private. It was also perfect, and mind-blowing, and something that he knew was special between the two of them.

Finally, she said, "so you'll talk to Marti and make sure she's okay with… the plan."

He smirked and nodded. The plan… Would that be the new euphemism that they would use to refer to them, together? What would they call it later if they successfully got their parents back together?

"Sure," he agreed, and couldn't help himself as one of his hands found itself back to her waist and pulled Casey toward him, pressing himself firmly against her body. She stumbled a bit from his force, and put her hand on his chest to steady herself. "I'll talk to her tonight," he said, and then, with eyebrows raised, added, "about the plan."

Casey smiled, but was unable to say anything more because Derek kissed her again. She responded immediately, tracing her hands up his chest to his shoulders, letting them play with the collar of his shirt.

His hands found their place again on her bare skin, and just as Derek was about to lift Casey on to the stack of gymnast mats behind her, a shrill ring! sounded out in the gym, and both Casey and him opened their eyes, frozen in place. The lunch period was over, and Derek would have cursed if he hadn't had his lips against Casey's. Before Derek pulled away, he closed his eyes and kissed her deeply one last time, before he let their bodies part. Every inch of him ached without her touch, and he moved to the side to let Casey reorganize her clothes, smoothing out her shirt that Derek had pleasingly ridden up her stomach.

"Do I look okay?" she asked, making sure her hair was put back into place, neatly pinning it again to make sure the stray hairs didn't give anything away.

Derek took his time to examine her person, letting his eyes linger on spots of her he would never have allowed Casey to catch him doing before.

She swatted the side of his head and glared at him. "Eyes up, swine," she reviled.

He smiled widely, realizing how much fun a relationship with her would be. He lifted his hands in surrender, and then let out an amused chuckle. "Hey, I'm just checking to make sure everything made its way back to the right place."

Her glare was intense as she crossed her arms, trying to cover up her chest as she made her way past him to the door. He wasn't completely oblivious to the coy smirk that played deviously on her lips as she elbowed him in the chest. "Remind me to wear a flour sack next time we meet like this," she joked, knowing that those things were supposed to be unbecoming to a lady's figure.

He couldn't wipe the smile off his face. "It wouldn't matter. You'd still look good."

She lifted her head regally and 'hmph-ed' before she put her hand on the door knob and twisted it open. She leaned her head out cautiously into the gymnasium to make sure the coast was clear, and then turned back to him.

"Wait here a minute while I go out first so that no one gets any ideas," she commanded.

He wanted to argue that he didn't care if anyone got ideas, but knew that Casey was more modest than that. She would die if she thought anyone knew she had just made out with Derek, her step-brother. She left him alone in the equipment room, and he smirked to himself. It would only be a matter of time before the other people at school found out, and that's when things would get interesting.

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