A/N: This is my first Life With Derek story and I've not watched all of the episodes yet, so I'm going to try to not be completely specific with certain things that has happened in the show as I don't want to get something wrong. I'm only on season 3 at the moment, but I've read a few Life with Derek Fan-fics and so far I think i can tackle this challenge. This will be a Dasey story, so if your into Derek and Casey getting together then great but if your not then don't read it. Thanks :)

Disclaimer: I don't Own Life with Derek

In Another Lifetime

Chapter One:

Casey couldn't help but stare at Derek in the school hallways as he talked to his best-friend Sam, about something she couldn't hear due to not being close enough to him. She was attempting to listen to her own best-friend, Emily but somehow the oldest Venturi was distracting her. He had that laid-back grin on his face and Casey couldn't help but day-dream about what it would feel like to just suddenly walk over there and kiss him so deep that it would make even; Derek Venturi weak in the knees.

"Casey, are you even listening to me?" Emily complained, bring Casey's attention away from Derek and back to her.

"Um... Yeah" Casey lied unconvincingly; Emily raised her eyebrows in response.

"Sorry Em, I got distracted" Casey admitted.

"Its okay, what's up Casey?" Emily wandered, concern now spreading across her features.

"Nothing... It's no big deal... It's nothing, I can handle it" Casey mumbled, starting to get herself in one of her 'Casey Freak outs'.

"You can tell me, Case" Emily assured her, Casey nodded taking deep breaths.

"Yeah, I know... I'm just not ready yet... Is that okay?" Casey asked, unsure of herself. Emily just nodded as they started to head off in to the direction of their next class.

Casey wanted to tell Emily what was going on inside her head but she couldn't, after all Casey was still completely confused over the whole thing herself and although Casey was a smart girl and knew that all logic suggested that she should tell someone else to help her make sense of everything, she just couldn't bring herself to even say it out loud just yet.

Later that night a knock on Casey's bedroom door startled her and she was reluctant to get out of her comfy bed to answer it so she just uttered a simple; "Come in" to whoever her visitor was.

She hoped it wouldn't be Derek but she also hoped it would be, the poor teen didn't even know what she really wanted right now. The door slowly opened to reveal Derek in his Pajama pants no shirt. She couldn't help but stare at his perfectly toned body, though also bruised in some places. No doubt from all that Ice-Hockey he played.

"Derek" She finally spoke, pulling her eyes away from his body to look at his face which was sporting his famous grin that Casey liked so much.

"So, case... I have a question" Derek announced, she nodded as she went over every possible scenario in her head wandering what he could possibly have to say.

"Yeah?" Casey replied, sitting up straight in anticipation. Derek chose that moment to quietly close the door behind him and come closer to Casey's bed before placing himself on the edge.

"Why were you staring at me, earlier?" He asked, in a jokey tone but Casey took it to heart and started to panic.

"I..Uh.. I wasn't staring at you... When?" Casey mumbled, but blurted out the last part. Derek chuckled and Casey wandered what that meant. Was he on to her? Did he know what she didn't?

"At school today, I was talking to Sam by my locker and you were full on staring at me!" Derek accused, that smile still on his face.

"Oh... I wasn't staring at you intentionally. I was just staring off into space" Casey lied hoping it would get him of her back.

"Oh yeah... And you expect me to believe that? Come on Case, you know you're not very good at lying... Do you remember our pet dog that died?" Derek pointed out, Casey sighed heavily.

"It's nothing, can't you just drop it Derek?" Casey pleaded, Derek chuckled.

"Come on, Space-Case... You know me better than that, now!" Derek laughed. "Just tell me, I'm sure I won't bite" Derek added.

"Fine, if you must know. I realized something, Happy?" Casey admitted, not wanting to give to much away.

"Oh yeah, what did you realize?" Derek wandered, he was now desperately awaiting her answer but he wouldn't let her know that!

Casey looked him in his eyes for a brief moment before tearing herself away to stare at her duvet cover.

"It's complicated" Casey admitted, Derek sighed but decided to let Casey have this one and slowly left her room closing her door behind him. Casey let out a breath she hadn't been aware that she was holding as soon as she heard the sound of Derek's own door opening and slamming behind him.

"I want you, Derek" Casey whispered to herself, before sinking back into bed and falling asleep.

Derek struggled to sleep that night, thoughts of Casey were swirling around in his mind and he couldn't make sense of it all. He wandered how a girl that he'd never got along with could make him feel so... fluttery inside. It hadn't been love at first sight and Derek wasn't exactly sure that it was even love in the first place but what he did know was that Casey MacDonald, had a special place in his heart. He shuddered at the thought that Casey was making him so corny, this wasn't like him.

Saying all of that Derek knew that he couldn't actually go for Casey, even if by some bizarre circumstances she did like him back because the brunette beauty was his step-sister. Derek knew that it wasn't wrong, they weren't related in any shape or form but still it would cause a lot of problems and awkwardness if he were to actually act on his feelings for, Casey.

Although, Derek still did want to date her and he was currently trying to figure out all of the ways to find out if Casey liked him back without actually giving anything away or embarrassing himself or her and without making things awkward if she didn't like him back. Of course an old method would be to read her diary but the chances of her actually saying anything about him were slim to none, as anyone could sneak into her room to read it. Even if she had put anything in there about him he was trying to turn over a knew leaf and change, slowly but he was trying tot to do petty and childish things like read Casey's diary.

That wouldn't exactly but him in her good books and it could seriously ruin his chances with her in the future, you know if he even had a chance that is. Of course the old Derek wouldn't be blinded by his growing infatuation with the teen who lived in the bedroom next to his.

A/N: I hope I kept everyone in character but if I didn't let me know, I hope you liked the first chapter as much as I enjoyed writing it. Review please, thanks for reading :)