Author's Note: Thanks for all the reviews. Those of you who have LWD fics in progress, please update as soon as you can cuz I miss reading them! lol. Okay, this fic was supposed to be rated Mature but since I made it less explicit so it could have a T rating. So, there is sex in this chapter, but it's not at all explicit. But if you're offended by it or anything, don't read it. Just giving you the heads up. Casey has this need to prove something to Derek, I guess. She's so stubborn.What has she got planned? Hmm...

I waited until everyone was asleep. My whole body was shaking with a mix of anger and apprehension. I knew what I was going to do next was wrong on so many levels. But I just needed to prove it to him.

I needed to.

And so I put on my sexiest little number that I could find. A black lace ensemble that I had bought with a bunch of my girlfriends last summer at some lingerie sale. I had never worn it before.

It looked amazing.

I brushed my hair down so it was a mix of wildness and innocence. Tempting and seductive. Then I made my way to Derek's room.

I saw his light was off and I didn't bother knocking. I crept inside, shutting the door behind me, and flicked on every light in his room.

Derek sat up immediately in his messy bed, his hair sticking out in every direction, his blanket barely covering his simply boxer-clad body.

"Casey? What the hell are you doing?" he asked, rubbing his eyes in a pissed off voice. As soon as his hands were away from his eyes, I watched his jaw drop. His eyes scanned my body, from my bare feet to my alluring smile and twinkling eyes.

"Teaching you to call someone a prude," I said in a sexy voice, sashaying my way over to his bed.

He didn't make a sound as he watched my climb onto his bed and straddle his body. His eyes lingered on my lips and I smiled, leaning down and capturing his lips with my own. The kiss deepened, and his tongue slid into my mouth with expert ease. Wow, he was a better kisser than I had ever imagined.

Uh… not that I had ever imagined kissing my stepbrother or anything.

I pressed my body against his as our passion increased. I had only meant to make out with him a little, just to teach him that I wasn't the prude he thought I was. Rile him up a bit. Get him thinking about me on a different level, even. But I never expected it to go as far as it did…

"I take it back, Case," he murmured as clothes began coming off. "You're definitely no prude."

I grinned proudly at that. I mean, that was all I had wanted. To prove to my stupid stepbrother that I could be just as seductive as one of his little girlfriends or whatever.

I mean… that was all that I wanted, right?

Lying there scantily clad with Derek on top of me, giving me a look that said, "I want you now," I wasn't so sure anymore.

We continued. His face was priceless.

I gave him the okay, and he suddenly pulled away, grinning sheepishly down at me. "I wanted you from the beginning, Casey," he whispered almost guiltily, the heat of his breath soft against my open lips.

"Shh…" I whispered coyly, pressing a finger against his lips, which he instantly pressed a gentle kiss to. Now knowing what I really wanted, I positioned myself under him, my blue eyes looking deep into his sexy dark ones. "I want you too."

He smiled down at me, a look of transfixion on his face as he registered what I had just said.

"It'll hurt…" he warned.

I pressed my lips against his, my hormones getting the best of me. "Do it," I murmured against his mouth.

And that was that.

I woke up early the next morning cuddled up with a naked body.

Cuddled up with a naked Derek.

"Oh my gosh!" I gasped, instantly sitting upright.

Derek looked over at me, his eyes heavily-lidded with sleep. "Shh, Case, go back to sleep," he groaned, pulling me back to him.

I just stared up at the ceiling, trying to collect my thoughts. I had just wanted to get him worked up. I hadn't wanted to sleep with my stepbrother.

Okay, maybe that was a lie. I sort of always wondered what it would be like to sleep with Derek.

But I didn't actually think I would!

I looked over at him. He was so…cocky. So annoying. So—

I stopped when I felt him put his head on my bare stomach, giving it a soft kiss before falling back to sleep.

I felt myself melt at that. He was so cute. And sweet. And surprisingly gentle. He had asked a million times if I was okay, and made sure to go easy on me so I wouldn't be in much pain.

I ran my hand through his hair as if he were a little boy, which was what he looked like asleep. All angelic and so not himself.

"Oh Derek…" I whispered, not knowing what to do. So I just closed my eyes and fell back to sleep, my mind on overload.

I woke up a few hours later to Derek sitting on the bed, pulling his sneakers on. He was fully dressed, and his hair was wet from the shower.

"Oh no!" I bolted upright. "Am I late?" My eyes searched around his room quickly for a clock.

Derek looked over at me. "Nope, it's still early." He gave me a grin and moved up to where I sat on the bed. I suddenly felt very uncomfortable and pulled the sheets up to hide my body.

He noticed what I was doing. "You shouldn't hide yourself, Case. You're beautiful." He reached over and cupped my cheek, pressing a soft kiss against my lips before getting off of the bed and standing, once again leaving me completely shocked.

"Go get ready," he winked. "Edwin will be trying to get the shower next, and he takes forever." He gave a classic Derek grin but with softer eyes, and left the room.

I sat there, completely mystified.

I took a shower as quickly as possible, and pulled on my clothes. I brushed my hair and put a little bit of make-up on. I left my hair down, not having time to pull it up, and grabbed my backpack. I was simply on automatic. I jogged down the stairs, to where my whole family was eating breakfast.

"Morning, Sweetie," my mother smiled. "I made pancakes."

I shook my head. "No, I gotta, uh meet Emily before school. Bye!" I practically ran out of the room.

Once outside, I stopped completely. Emily.

I couldn't tell Emily. She had a crush on Derek. And apparently for a long time. Plus, what would she think of me? I mean, I was his stepsister. I sighed.

What did I think of myself?

I avoided Emily a lot that day. And Derek, actually, too. Because I was confused. He found me after school, though, on the walk home.

I had stopped for no reason, just standing in the middle of the sidewalk with nobody around, just thinking. Did I feel something for Derek? Was it a crush? Was it just my body and hormones wanting to, for lack of a better term, get laid? Or was it something else?

That's when I felt two arms slither around my waist. "I like your hair down," Derek whispered against my neck, instantly causing my body to shudder although it was seventy degrees outside. "You should wear it like this more often."

I closed my eyes for a moment, and then turned around to face him before opening them again. "Derek…" I looked at his cute smile and sparkling eyes. He just seemed more alive than the Derek I was used to. I started say something, but then stopped, suddenly losing all words. I simply sighed.

He smiled. "You can't deny it, Case," he laced his hand through my own. "We were unexpectedly amazing together last night."

I didn't respond. I didn't know how to reply. Yes, we were mind-blowing? Yes, I had never felt so much pleasure in my life? Yes, I want to do you again now!

"Casey?" he waited for a response.

I let out a long breath. "Yes, it was amazing!" I practically yelled out and then blushed at my reaction. I hadn't meant it to come out that loud.

Derek chuckled a bit, but grinned all the same. "Meet me again tonight." He pressed his lips against my ear. "I'll be waiting." With that, he took off, leaving me in the dust to wonder what the hell I was getting caught up in.