I don't know why this idea popped into my head, but it seems that I can not update any of my fan fiction unless first writing this. I don't really watch LFD that much, so if theirs little mistakes, don't kill me. But I do really like the show, I'm just busy and never catch it on. I think it's the only hope at a normal Disney show like the ones that I loved when I was a 'tween' or the first couple of teenage years. Like Lizzie McGuire and Even Stevens. Shows were money wasn't handed out and new cell phones weren't the shows biggest problems haha. Anyways, I came up with this idea last night, and I've been trying to update my One Tree Hill story ever since, its not working out for me, so I decided to give this a shot, so be nice and please review! Keep in mind, this isn't my first fan fiction, but it is my first LFD one. And yes, before you asked, the title of the fic is also a song by Taylor Swift. The song is basically the reason I came up with the entire thing.

Tied Together With a Smile

-Intro-

Derek Venturi could loudly hear the familiar sound of an old Christina Aguilera song blasting from an upstairs bedroom the second he got into the house. It was a Saturday morning an there had been a message on his phone about the family going out to breakfast, in which Derek didn't get until he woke up later with a killer headache. Too much tequila the night before maybe? He had said he was with the guys, which wasn't a complete lie, but he didn't mention the party, or the alcohol.

The sound of the high pitched voice was making his head hurt worse, so without thinking he ran upstairs and into Casey's room. But what he saw made him stop dead in his tracks, there she was. The girl that always got on his last nerve, the girl he was convinced he hated, dancing around in a barely there pair of black lacey boy shorts, and a matching lace cami that came just above her belly button, and absolutely nothing else.

Her face had no makeup on it as she jumped around singing the words of "genie in a bottle" with her hair flying everywhere. He had never seen her look so beautiful. He wasn't stupid, he knew Casey was attractive, but he could never admit that, after all, she was his step sister. But watching her seem so carefree, unstressed, not to mention undressed, it was something he had never mentioned, and it was having a clear effect on him, and there was no denying that.

Derek noticed he was staring, and tried to look away, just in time for Casey to whirl around and see him standing there. She shrieked, staring at him for a second trying to register what was happening. Why was he just standing there smirking, why was he still staring, she had no idea, but she quickly turned of the music and grabbed the nearest piece of clothing to cover her body.

"DER-REK!" she screamed in her normal tone, covering the lower part of her body with a towel, "what are you doing?!" she screamed again, causing him to jump and look away. But with in seconds he recovered and started spitting out an excuse.

"well I was trying to go back to sleep, but when I came in you were blasting that sorry excuse for music" she snapped glaring right back at her, reaching forward and pinching an almost nonexistent piece of stomach fat. "Maybe you should cut down on the junk food, chubs" he said trying to spark a reaction so that she would be so mad she wouldn't notice the bulge forming in his pants. It worked as she quickly went from a rage of anger to looking completely crush, which did make him feel bad, but he had to get out the current situation.

"Get out!" she screamed pushing him towards the door and slamming it. Once in the hallway he sighed, looking down at what clearly Casey had done to him. It made him feel so horrible, dirty even. That his step sister could actually turn him on that much. Trying to shake all thoughts from his mind he headed towards the bathroom, mentally preparing for the ice cold water he was going to need to force himself under.

Meanwhile though, Casey had thrown the towel to the side again and was now examining herself in her full length mirror, poking at her stomach. She tried to tell herself that Derek was just trying to make fun of her, trying to get her going, but in the back of her mind the chanting of her Jr High nicknames were starting to come back to her.

Not that anyone in her new family knew about her past, but Casey suffered from an eating disorder from the age of 13, and finally got help around her 15th birthday, only months before her mother married George. From the time she was 9, Casey was kind of chubby, finally sick of being teased when she started to get into her teen years, she decided to take matters into her own hands, quite literally. She wouldn't eat for days, and then she would binge and purge. She constantly worked out, causing her to nearly collapse more than a few times. But no one seemed to notice, until she was 14 and a half and she was running in gym and passed out, the doctors said it was starvation, and diagnosed her as bulimic. They could tell from the redness of her throat that she had often made herself throw up, and against her own will she was put into rehab, only returning to school 3 full weeks before entering the new family.

Though Nora watched her carefully, Casey made both she and Lizzie promise they'd never mention it. It was hard enough being the new girl, Derek's step sister, let alone the girl with an eating disorder. So for the past two years she never mentioned it. She was doing so much better, gaining a little weight back, and was now at an almost normal weight. But like with any girl, she still had her self doubt. Often thinking she was fat, but never saying it out loud in fear of what her mother would say or do.

But now every feeling seemed to pour back into her. Looking in the mirror she would swear she saw rolls of extra weight that didn't truly exist. And just thinking about the feeling of Derek pinching it, pointing it out made tears form in her eyes. And before she knew what she was doing, she was rushing towards the downstairs bathroom and throwing the food she had consumed the night before up.

After staring into the toilet for what seemed like hours, but was really only seconds Casey stood up and flushed, running cold water over her face and running back up the stairs after hearing the sound of car doors closing outside.

It would only be this once she promised herself as she got dressed. It was just a slipup, it meant nothing. But the feeling of his fingers still made her blood go cold, and her eyes well, and of course made her wonder, why did she even care what he thought.

Just a start, enough replies will make me update. I know it's a little out of character, but like I said, I don't watch often. & Also, if you haven't noticed it is a little into the future, Casey and Derek are both 17, which is why the alcohol, and sexual tension is more apparent.