A/N: Please Read. This is my first attempt at a fanfic and I'm Portuguese so sorry if there are some grammar errors during the fic. It's my first so I would appreciate reviews to help me improve my written. Rated M. Just for safe. Thank you (: Enjoy.

Disclaimer: I don't own Life with Derek or the characters.

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Casey's POV

I'm at the church front door. It's my mom and George's wedding. Today I'm going to meet my future stepbrothers. Or at least two of them.

George walks towards me.

"Hello Casey, I would like to introduce you my children. These are Marti and Edwin. I have other son you know, but I can't find him. He must be around here somewhere. His name is-"

"Derek, pleasure" said a familiar voice behind me.

"I'm Casey" I said as I turn around to face him. He stared at me for a few seconds.

"Have we already met, Casey?"

Oh yes. If only I could tell you.I thought to my self.

"No, I don't think so" I answered in a calm voice, so that no one notices I'm lying.

Derek spent the entire ceremony looking at me. I just wish he doesn't recognize me.

The ceremony is over. We are now going to lunch. We are going to be closer now.

I've just entered the restaurant and I hear Derek whispering at my ear:

"Come to the bathroom please. I need to ask you something."

I follow him because I don't want to seem rude. When we reach the bathroom he asks:

"Why do I think I know you Casey?"

My heart is beating a thousand miles.

"I don't know. Maybe you've seen me somewhere. A…At the mall or something. I dunno" I answered nervously.

"You know Casey; I think you're lying to me. I don't like when people lie to me. And I will find out who you are Casey MacDonald." With this he left the bathroom and I staring ate the door he just went through, my heart beating fast, very fast.

Derek's POV

I left the bathroom. I've just met my new stepsister. The strange thing about all this is that I think I knew her before. But strangely I can't remember. Usually, I always remember a cute girl. Yeah, she's cute. I wish she just tell me the truth. I know she is lying to me. I can feel it. And I don't like it.

-- Six months later --

"Derek!" I hear a voice from upstairs. It's Casey yelling at me. As usual. I can hear her come down the stairs very fast. I don't even have time to say something.

"Why did you do this to me? Why did you threw most part of my clothes out of the window? They fell into the wet grass and now they are all wet and today I'm going out with Emily! What am I going to do now?"

"Calm down Casey. It was just a small prank. I'm sure you figure something else to dress. I didn't threw all of your clothes." I answered with a smirk. "Now if you don't mind I need to go to my hockey practice. Bye Case."

I could hear her insulting me at my back. It makes me sad. I like her. I really like her and I'm sick of this! I'm sick of playing pranks on her. I think she hates me now. I wish she knew I only do this to see if I could really get on her nerve and make her tell me where did we met before. I'm sure we did. I even tried to make her jealous with Emily but she doesn't give up. Everyday she lies to me. But Derek Venturi don't quit. If I can't make her tell me, I will find out for myself.

Normal POV

Derek came home from his hockey practice. He was tired and sweaty.

"I'm going to take a bath now and when I finish it I will profit the fact Casey isn't at home and I will search her room" Derek thought to himself.

Derek entered the shower. The water was very hot but he didn't mind. It was cold outside and after two hours of practice it felt like heaven.

He was thinking about Casey.

That girl has something special. There is something about her that I can't understand. And it's not the fact that she's beautiful and lovely and the fact that I…I love her. Thought Derek.

Derek doesn't think this feeling was bad. They were step-brothers so it was ok to the law and everything. He didn't told her yet because he thought it's just to weird and he didn't knew what she would tell or feel.

Derek closed the water. He went out of the tub and dried himself. He put his boxers on and left the bathroom moving towards Casey's room.

He starts looking around the room. At first sight he founds nothing. He starts looking in her shelves. Nothing either. Then he opens her bedside cabinet drawer. He found a little blue book which says Diary on the cover. As he opened it something fell onto the floor. He picked it up.

It was an invitation to a summer party at the beach at 10:30 pm. Attached to it was a photo with a boy and a girl. He looked closer. It was Casey. And right at her side there was…

"Derek?! What are you doing at my room searching my stuff?" asked an incredulous Casey.

"Well Casey I think you've got something to explain to me" said Derek showing her the picture he found along with the invitation. He seemed mad, yet confused.

Damn.Casey thought. Now I've got to tell him.