Author's Note: Hey guys, this is my first LWD fanfiction. It'd be great for some reviews and criticism. Hopefully you guys will like it!

"I hate you Derek Venturi." I yelled as I slammed the door to my room. He was so irritating. I don't know what I hated most about him; the fact that he was so cocky and confident, always sure about himself or the fact that I Casey Macdonald secretly loved it. Not that I was in love with him, ew. That would be incest, kind of, because we aren't exactly related, at least not by blood. What am I talking about? There is no way that Derek and I would ever be together, even if our parents weren't married.

"Just to let you know Case, I didn't talk Sammy boy into dumping you." Derek screamed as he pushed open my door.

"Get out of my room Derek." I yelled as I got up from my bed.

"Make me." He countered.

I rolled my eyes. How pathetic. "Fine. Just stand there. That's not going to make me talk to you," I turned from him and plopped myself down in front of my laptop, intending to get down to homework. But it's not easy trying to concentrate when someone is staring daggers into your back. "What do you want Derek?" I sighed in frustration. Not even facing him, I could tell that he was smirking at me.

"I told you. I don't want you to think that Sam dumped you because I told him to, because I didn't."

I swiveled around and glared at him. "Oh yeah?" I replied lamely. "Why else would he break up with me?" Derek folded his arms and leaned against my doorframe, looking really attractive with his brown messed up hair and dark brown eyes. My own blue eyes skimmed down to the rest of his body to where his abs were, hidden behind those layers of shirts. I knew he had abs from the trips that we took to the beach with the family. Okay, so not the time to be drooling over his good looks. Actually, it's never a good time to be drooling about him. He startled me out of my focus of his delicious body.

"As if you don't know."

What? Oh right, Sam and I breaking up. Even though we hit it off really great in the beginning, the chemistry between us died. After the first few dates, we fell into a loop, often repeating conversations we already had. Don't get me wrong, Sam is a great guy, I just don't think that he's the guy for me and I guess towards the end, we both felt that it was time to finish it. Sam officially ended it with me a few days ago and we are still on rocky territory, though I'm sure we'll be friends soon enough. But I was still heart broken, Sam was my first boyfriend and so for the last few days, I've been taking it out on Derek, actually you can say that I've been taking a lot out on Derek. Which I know is completely unfair for him. But I couldn't help but feel that Derek had something to with the end to my already diminished relationship.

I couldn't let my step brother have the last word, so I decided to play dumb. "Sorry Derek, I don't know. Why don't you enlighten me? Tell me, why did Sam and I break up?"

For a second, I seriously thought that for once Derek Venturi had no reply, that I had won this round. All Derek did was stand in my doorway seemingly trying to stare me down, having no answer to my question. I outwardly smirked at him.

"What's this? The great Derek has no answer," he still didn't say anything which was strange on his behalf but I ignored it. "I thought so," I turned back to my laptop; ready to really get down to work. "If you could be so kind, please close the door behind you." I said tapping away, staring at my monitor. I heard the door shut and assumed that Derek had gone back to his room thinking up some scheme to even the playing ground with me, for the short number of years that I've known him; Derek has never quietly accepted defeat.

"You weren't into him." Croaked a voice from behind me.

I let out a scream and turned around to face my bed which was currently under the none too conspicuous Derek who was leaning against the bed frame.

"Derek! I thought I told you to leave." I breathed out hard, grasping my heart in what I guess was in an over dramatic way. I hadn't even processed what he had to just said. He smirked once again. I wanted to wipe it off his arrogant face.

"Did you not hear me Case? I said you weren't into him," He continued smirking but leaned his body over closer to me. "And you never told me to leave, you just told me to close the door, which by the way you have not thanked me for. But you're welcome anyways."

I stared at him in confusion. Only Derek could make me lose my cool, turn my organized life into utter chaos, make me forget things and react without thinking first.

"You asked me why Sammy ended things with you and I think the answer is that you were never into him."

"What are you talking about Derek? Of course I liked Sam, why else do you think that I would go out with him." I once again rolled my eyes at Derek's stupidity, though I myself have no idea why things are the way they are.

This time, Derek wasn't quiet. "You only went out with him because you couldn't have what you really wanted. You were using the poor boy to distract you from your real goal."

I crossed my arms and stood up. "Oh, is that so? Tell me then, what is my real goal?" The jerk, trying to act as if he knew me, who does he think he is?

He stood up as well. Wow, I never realized how tall he was. Still, he wasn't going to use his height to make me back down. My room was pretty small so with the both of us standing, we weren't that far apart. I looked up at him and stared him right in the eye. He stared right back at me.

"Me." He growled and slammed his mouth against mine. Oh God, he was so good. I wanted this, but the sane part of me kept trying to fight, telling me it was wrong for us to be together. I raised my arms, ready to push him away, but instead I reached around his head and pulled him closer to me, so that our bodies were molded together. This was right, it felt right. No matter how many times I've kissed Sam, it never felt like this. He slowly ran his tongue against my lips, which I gladly opened, the second our tongues touched, I swear I felt perfection. I don't know how long it lasted, but by the time we pulled apart we were both panting heavily and strewn across my bed, with me on top of him.

Slowly I collected me bearings and got off him. I looked at him, ready to say that we should both pretend that never happened. He beat me to it, but he didn't say what I thought he was going to say. "Don't say it didn't feel right Casey. Don't tell me that it was a mistake. Look at me Casey," for I had turned away from him. He gently grabbed my face and turned it so that I was once again facing his astonishing brown eyes. "Look at me. We both know that you and Sam were never going to make it. Not when you and I…"

He didn't finish. I pulled away from him. "Derek, it was wrong. You and I are brother and sister."

"Step." He interrupted.

"It doesn't matter. Our parents are married, we," I gestured between us "we can never be a We. It just isn't right, it's freaking incest." I practically jumped off my bed, ready to get as far away from him as possible.

He grabbed my arm and I felt tingles shooting all the way through me. "Do you see me as a brother Casey?"

"What? No!"

"Then there you go. It's not incest, we aren't blood related and we don't see each other as siblings. Our parents can't blame us, they put us together," He pulled me towards him so that we were touching. I couldn't believe this, doesn't he know that society frowns on this kind of thing. We could never work out. "I don't care what other people say Casey, especially when we…" he looked down at me, telling me to finish the sentence for him with his eyes.

"When we what Derek?" I whispered not taking the bait.

"Love each other." He said claiming my lips once again, only this time much more gently. He broke the sweetest kiss I ever experienced and told me what I don't think I would ever tire of hearing. "I love you Casey Macdonald."

I couldn't help but smile. "I love you too." And hugged him, sealing the deal that we would endure whatever comes our way, together.

He pulled away from me slightly, and I expected him to make life time promises of forever. I should have known better.

"You know," he said as he started raining kisses on my jaw. "I really didn't tell Sam to break up with you. To think that he knew not to mess with what's mine."

"Derek?" I sighed as he reached my neck.

"Yeah baby?" he said between kisses.

"Get out of my room."