This fic takes place after "Surprise". Derek has gotten back together with Kendra, instead of dating Emily. (I hated that they ended up together. She is so annoying and the writers seemed to put it there just to dissapate the tension between Casey and Derek). They have had their prom but school is not yet over. (My twin sisters high school had their grad almost 5 weeks before they finished school).

This fic is rated M for one lemon in later chapters.

This is my very first fic and I would love to hear your feedback. Please be gentle, if you can help it, I haven't done any creative writing since high school and I am just getting back into the groove of things. I hope you like it.

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Breaking the Rules

Chapter 1: The Proposition

She was waiting for Derek in the parking lot of the High School and he was late for the billionth time this week. Ever since he got back together with Kendra they spent every waking moment together; god forbid Kendra missed her "Der-bear". She could see them, from where she stood, making out on the front lawn. Now that Derek had given up his anti-PDA laws they were always all over annoyed her and she didn't know why and for the first time in her melodramatic,over-analyzed life she refuesed to think about it.

Derek strolled towards the prince with a big smirk on his face. She wished that she could do something to wipe it off his stupid face but she had nothing.

"Wow! 35 minutes late that has to be a new record Derek"

"What can I say, you're not the only overachiever in the house" his smirk grew and it infuriated her. "If it bothers you take the bus or better yet don't come home at all".

"I wish I could so I could get away from you and your...stupid face"

"Nice one Case" Derek said sarcastically.

On the drive home Casey got a phone call and when she picked it up she heard a loud squeal.

"OH MY GOD!" it was Emily in the middle of a spaz "You will never guess what!"

"Ok, so tell me" Casey said laughing at her excitable friend.

"ThereisanewclubandIgotussomeids" Casey did not understand.

"Come again?"

"There is this INSANE new club in town and I got us some i.d.s!"

Casey paused to think about what Emily had just said "Hello, Casey are you there?"

"Yeah, Emily I don't know about this...."

"Come on, you HAVE to go! There will be cute guys, great music and...cute guys"

Casey never drank....ever and she certainly never did anything illegal. "No Emily I can't go with you. It's not right to break the law and...and.."

She realized how lame she was sounding when Derek turned to her and laughed.

He grabbed the phone, "Emily whatever naughty thing you are up to I don't think Casey is going to go. She's too busy worrying to have any fun"

"Is that you Derek..." Emily said as Casey grabbed her phone.

"Emily?" Casey's question was met with silence, "Hello"

"Oh, Casey, yeah, um, hi" Emily stuttered, "that was Derek!"

"Yes that was, that jerk just stole my phone!" she said reaching over to smack him.

"He said I was naughty! Oh my god this is the best day ever"

"I'm glad you're enjoying it" Casey said sarcastically, "About this club I simply can't bring myself to break the law, no matter how lame that sounds. It is a matter of principle and what are we without principles! We're animals! We're ...."

"Derek" Emily added. "If you won't go with me I am not going to go alone. I guess I will just sit on these and pray that you change your mind."

"Thanks for understanding Em, but I don't think I will change my mind" The girls hung-up and Casey tried her best not to make a comment about the issue to Derek. She could see him from the corner of her eye, staring, smirking, laughing to himself about his super lame step-sister.

Despite her best efforts to avoid a conversation he spoke,"What is Emily proposing to you that will land you in jail? Let me guess, not returning library books?"

"No, for your information, she invited me to go to a club tomorrow night, with illegal i.d.s" she added "How dare you think that my friend would suggest that I commit theft she knows better, she has morals and principles like me."

"Doesn't sound like it. Sounds like she knows how to have fun unlike you Basket Case"

For the first time, Casey did not try to make a comeback. She had nothing because she doubted whether or not she was right. Maybe he was right. Maybe she didn't know how to have fun....

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At supper that evening the family was having their typical banter about the bad food and the bad days they were having. Lizzie and Edwin were fighting over a class project, Marty had decided to steal other kid's toys again and Nora and George were trying to keep everyone in order. Surprisingly Derek and Casey were quiet. Casey was contemplating her relationship with Emily and Derek seemed distracted too. Casey wondered what he was thinking about but decided that since Derek wasn't capable of thought, he was likely just spacing out.

Suddenly Derek's cell phone rang and as George yelled "NO PHONES AT THE DINNER TABLE" Derek picked it up. He took his call to the kitchen. Casey figured it was probably Kendra and she groaned garnering looks from her family members. She didn't know why it bothered her so much that Kendra was always calling or showing up or necking with Derek. She felt a weird sense of hate for her and she didn't feel that Kendra was right for Derek. She pushed all these thoughts to the back of her mind.

From the kitchen Derek could be heard arguing with Kendra with increasing volume...."Well if I can't guess what is bothering you we can just drop it......No I am not trying to fight with you I am trying to kill this conversation.....No I don't want to kill are relationship Kendra, I just don't understand you, you were pretty happy earlier today....Yeah I had fun too....Yeah that was pretty hot....you are sexy...."

George intercepted yelling "DEREK DINNER NOW!"

Before hanging up Derek was heard mumbling and than repeating himself louder "Your Der-bear misses you too."

The whole family began to laugh at Derek and he began to object to their eavesdropping as he sat, grumpy faced, at the table.

Nora said "Don't be angry we won't do it again...Der-bear." Everyone began to laugh again.

Derek didn't notice but Casey wasn't laughing that nickname gave her a stomach-ache. God! she hated Kendra and her stupid prissy ways and her always bossing around Derek...that was her job.

Derek and Casey were on dishes that night and Derek, reluctantly, did his part "I'll dry, you wash"

"Fine" said Casey a little surprised that he had agreed to help her do the dishes.

Chapter 2: Secrets Revealed

While they washed Casey couldn't help taking quick glances at Derek. He was tall, slender but not scrawny and for the first time she saw the charm of his messy hair and his shining brown eyes and his smirk...

"What are you looking at? Spacing out again Case?"

Casey felt a blush come over her face "No, um I mean, yeah I was spacing out sorry..."

She could see that her apology puzzled him and in perfect Derek form he began to bug her to break this quiet, and slightly tense, moment they were sharing.

"So, still not willing to take Emily up on her offer to go to the club?" Derek asked with a smirk "Maybe I'll ask her out, she is looking better every year and..."

"Shut up!" Casey said a little louder than she intended, "and leave her alone. Besides she can't go with you; she has an extra i.d for me not for a guy"

"Well if the i.d is for you it probably looks like a guy."

"Der-ek!" Casey yelled. She stayed quiet for a moment watching him revel in his insult to her. It bothered her more than she imagined it would. Lately his comments bothered her more and more. She didn't like that he said that she looked like a guy, or that she didn't know how to have fun...

"So what is so great about breaking the law, I mean...have you ever done it?" Casey asked tentatively, reviving the conversation that they started in the car.

Derek didn't miss a beat, "I have broken a law or two many times and trust me" he leaned into her and her breath caught in her throat "It is alotta fun."

"Well, what did you do? to break the law"

"Well it's a couple of the basic fun guy stuff, breaking into places to hang out, stealing a couple things from the liquor store, going to bars and getting smashed and...."

He stopped and Casey was full of curiousity.

"And what? why did you hesitate?"

"You don't want to know Case, trust me. I think it's a bit grown up for you." He was taunting her but she didn't care; she had to know what it was.

"Tell me Derek...please."

"Ok, but don't say that I didn't warn you." He hopped up on the counter and directed her to sit on the stool nearest to him. She sat down never losing eye contact.

"Well, one night me and Kendra were having a couple drinks at a party and decided to go for a walk, to get some privacy" he smiled and raised her eyebrows hinting at what she already knew he meant."We found this abandoned park where we were completely alone. Kendra started getting pretty frisky and she couldn't keep her hands off me, naturally" She rolled her eyes but he continued, "I guess she was feeling pretty wild that night because she stopped kissing me pulled my pants down and gave me a blow-job right in the middle of the park."

Casey's eyes were huge at that moment and Derek waited for the "eww Der-ek!" he knew was coming but he didn't hear it. Instead he saw Casey look down at her feet thinking and looking a little upset.

"I warned you Case, the story is pretty racy but you insisted on hearing it. You can't be mad. Your not mad...are you?"

"Of course not. Why should I care about what slutty things Kendra does in parks" Casey replied, sounding a little more catty than she intended.

"What you call slutty, I call spontaneous and fun. But you wouldn't understand that because you're so boring." Derek hopped off the counter and went upstairs.

Casey remained downstairs thinking. Despite the fact that she was fully aware that what Kendra had done was totally slutty and supremely gross she couldn't help but acknowledge that she was having fun. Casey never had that kind of fun. There was no wildness in Casey which Derek had very eagerly pointed out. She stopped thinking, picked up the phone, and dialed.

"Emily, it's Casey. Your right, I've changed my mind I'll go to the club with you."

Chapter 3: At the club

Derek stood in the bathroom, half dressed getting ready to see Kendra. The door was half closed and his slender yet muscular body could be made out through the gap in the doorway. At this moment Casey walked to the bathroom to find her brush and saw Derek. She stared. Her thoughts about his height and his body rushed back into her mind. In the two years that they had lived together she had never seen him this naked and she couldn't help but be impressed by the sight.

The door flew open, "What are you doing?" Derek said catching her standing in the hall.

"Uh, um, Nothing! I-I mean I'm waiting for you to stop grooming yourself so I can get ready too. You aren't the only one with plans tonight Derek." Good save, Casey thought to herself.

"Oh really? Did you decide to go to the club with Emily after all?" She curtly nodded. "That wouldn't have anything to do with what we talked about last night would it?"

"No! I made the decision on my own, thank you. and could you please keep your voice down, I don't want anyone to know where I am going tonight!"

Derek leaned into Casey and as he spoke he felt the warmth of his body nearly touching her, "You and your crazy secrets. If no one's asked you where you are going, don't worry about anyone finding out. Nobody cares. I know I don't". He began to walk away and than turned, "Stay out of trouble Wild Child" he said sarcastically and disappeared into his room.

Casey grabbed her brush and raced into her room to get ready. She did her best to make her self look nineteen; with a dress cut lower than anything she had ever worn and heels higher than she had ever used. She looked at least 20 and hot as hell.

While she was getting ready she could hear Derek on the phone, arguing "Look Kendra, I thought that we were done fighting.... You said that you wanted to come over and I got everyone in the house to leave and now your changing your mind!.....What do you want! Ugh! ..." the arguing continued and Casey could not help but hope that by the end of the night she would be rid of Kendra. I mean, she was making Derek grumpy and that wasn't good...for anyone.

Casey walked downstairs and found Derek on his way up. He stopped dead in his tracks and looked her up and down with his mouth open. She was now the one with the smirk, "Do I look of age?" she asked.

"You look great" he said without thinking. He blushed and she brushed by him hiding her smile. "Cover up." he said after a while.

"When is Kendra coming over?" Casey asked hoping that he would say never.

"Any minute, so don't chicken out and come back here early or your going to see something you rather not." he said with a big grin on his face. He was lying through his teeth and Casey knew it, but the thought of Kendra being at their house alone with Derek made her angry. She hid it well.

"Trust me, I'm going to have the time of my life, Don't wait up." she said as she sauntered out the door.

When Emily and Casey got to the club the line up was huge. It was cold and neither of them were wearing enough to keep warm. "This was such a bad idea! We are going to freeze to death before we get in!"

"No we won't" Emily said confidently.

"How do you know that?"Casey whined.

"I know how we can get in right now" Emily said, "All we have to do is go to the front of the line and flirt with the bouncer, he'll let us in for sure"

"I don't think that is going to work. He's gonna take one look at us and see that we are minors and then is going to call the cops and then we are going to go to jail and ..."

Emily stopped her "Would you rather try and get in my way or would you rather go home?"

Casey thought about how much Derek and Kendra would laugh if she came home at 11:30, "Fine, let's go".

"Hi Ladies" the bouncer said as they came to the front.

"It's pretty cold tonight" Emily said coyly making it hard for Casey not to laugh.

"You ladies aren't dressed for the weather" the bouncer said taking the bait. He looked at Casey.

Now or never she thought. "Well it looks pretty hot in there, maybe you could let us in so we can be hot too." It was such a cheesy thing to say! She was so embarassed.

"I think I better let you in then" said the bouncer with a smile as he opened the door; letting them in.

"I can't believe I said that" yelled Casey.

"I can't believe it worked" said Emily

The girls walked into the club and were surprised at how many people were there. The dance floor was packed with people dancing to the music. The lights and sounds were overwhelming and exciting and for the first time that night Casey felt confident.

Before dancing Emily bought the them some shots. Casey looked at Emily quizzically. "I'll line them up for us and than we toss them back one after the other ok, Casey?"

Casey nodded, still a little scared (she had no idea what they were drinking). They did the shots quickly and they left a burning feeling in Casey's stomache but they tasted like cherries and maple syrup.

They entered the dance floor together melting into the mass of writhing bodies. Casey found herself more comfortable than she could have imagined. Lady Ga Ga's "Poker Face" was playing loudly, and she loved it. She danced seductivaly letting the pulsing rhythms fill her and feeling the alcohol go to her head.

The music slowed down and the girls went to get another drink. This time they ordered little pitchers of Vodka and lime that tasted like Sprite and Casey could not taste the liquor. They sat down and she noticed Emily scanning the room. "Who are you looking for?" Casey asked.

"A cute guy! Dancing and drinking is only half the fun of going out." Emily yelled back over Jaime Fox's "Blame it on the Alcohol".

Casey was having fun with just the two of them but she knew that since Sheldon had moved to Newfoundland Emily had been feeling very lonely. She started to look around for a hot guy too. Through the crowd of people Casey could make out a girl grinding up against a guy in the most surprising and slutty way.

"Em! You have to look at this girl she is so gross! She keeps grinding on her boyfriend like she thinks they're alone!" Laughing, Casey pointed the couple out to Emily and saw her mouth gape open and her eyes widen. Casey looked again and her stomache flipped.

The dance floor had cleared and she saw Kendra, in a dress so short it looked like a shirt, grinding all over Derek. Casey swallowed hard and was overcome with a mix of anger and sadness that she could not control. She was jealous. Madly, heartachingly, jealous. Emily noticed Casey's angry look.

"Are you okay Case"

"Yeah, I'm fine, great" Casey lied "Let's have another round". Casey and Emily each got another pitcher of Vodka and lime. Casey drank it more quickly than she should have and hearing Britney Spear's "If you seek Amy" grabbed Emily, pulling her to the dance floor. Casey danced to the loud music and closed her eyes trying to forget what she had just seen. She bumped into a couple people while dancing but she didn't care, she lost her self in the music dancing like no one was there. When she opened her eyes she saw Emily making out with a guy that was way too old for her.

Casey felt like she should grab Emily and tell her to stop, but instead she decided to walk away. As she walked off the dance floor she bumped into a girl holding a tray of shots. The tray tipped and fell all over Casey. The waitress was pissed and as she looked around she could see a crowd of people looking at her and laughing. She saw Kendra holding back laughter and that did it for Casey.

Her eyes filled with tears and she left the club.

Chapter 4: When they're alone

By the time Casey got home she was exhausted and drunk. She fumbled with the keys trying to open the door as quietly as possible forgetting that Derek had convinced everyone to leave the house for the night.

Once inside Casey kicked off her heels and attempted to make her way up the stairs. She fell and instead of getting up decided to give up.

"Im gonna sleep here" she said out loud "In case anybody cares" and closed her eyes.

Suddenly the front door opened but Casey refused to open her eyes. She'd been caught and she knew it but she wasn't ready to face her screaming mother right now. She waited for the inevitable "CASEY!" but didn't hear it, instead she felt arms wrap around her waist.

"You're sticky Case." Derek laughed as he pulled Casey to her feet. She opened her blue eyes and looked sadly in to his brown ones, She sighed and placed her head on his shoulder, breathing softly on his neck. He swallowed hard and laughed a little. "You couldn't even make it to the washroom to clean up! You are a wild child!" he laughed again, louder this time.

"SHHHHHHHH! Don't talk so loud yer gonna wake everyone!" Casey slurred.

He laughed louder this time. Casey tumbled backwards pulling Derek down with her "I got rid of everybody tonight. Nobody is supposed to be here so ....." He was drunk too but not drunk enough to ignore how close their lips were. Her eyes were beautiful and her full mouth was so close he could almost taste it.

"So you an' Kendra could have sex in here" Casey said with a little anger in her voice. Derek snapped out of his trance and lifted himself and Casey off the floor.

"That was the plan" he said, reluctantly. She let go of his shoulders and steadied herself looking down, "But Kendra had other plans." he added as she began to crawl up the stairs.

"Wait Case" Derek called from the bottom of the stairs "You need to get cleaned up before morning"

Casey sat on the top step confused as Derek disappeared into the kitchen. When he came up the stairs he gave her two bottles of water and some donuts. She got up with a little help from him.

"Go to your room, I'll be there in a second" he said quickly going to the washroom. Casey went to her room and sat on her bed trying to piece together what was happening. Why was Derek being so nice to her? Where was Kendra?

"Drink the water and eat the donut Case" Derek said interupting her thoughts "Then take these asprins and you'll be fine tomorrow.

"Is this your drinking ritual, or does it really work?" she said smiling.

"It works trust me, I may not know chemistry but I know drinking" he smiled back at her. He could see now that her face was covered in multi-coloured syrup.

He got up and left her room again. Casey thought he was leaving for good and peeled her dress off.

When Derek re-entered he didn't knock, as usual, and saw her nearly naked body illuminated by the street lamp outside her window. He was mesmirized again and found himself aroused by the forbidden sight of her body. He let out a sigh accidently, which caused Casey to turn towards him.

"You always forget to knock" she said. There was a hint of seduction in her voice that Derek thought he imagined. He turned away from her realizing how wrong it was to look at her the way he was looking.

"Uh, um...sorry. I'll leave so you can get dressed" he stammered.

"Don't go too far, come back when I'm done." Derek was surprised by how calm she reacted to this encounter. Casey was surprised herself; she wanted him to see her and she knew it. There was no more denial. She wanted him, badly.

She put on a tank top and shorts and called him in again.

"I brought you a wet towel, to clean you up."

Casey sat on the edge of her bed, patting a space beside her. Derek sat as far from her as possible. She leaned in close to him and he assumed that she wanted him to wash her face which he began to do softly. As he did this she never took her eyes off him; he avoided her glance as best he could.

"Your a sweetie, Derek" she said.

"Just for tonight, so don't get any ideas," he answered "this is a one time deal. Next time you get yourself into trouble, you're on your own"

She smiled at him at stretched out on the bed. Having her body right there in front of him was too much for Derek. Her breasts, her legs, her beautiful face so close, almost begging him to touch her. He didn't and began to walk away.

"Tuck me in" she said, stopping him in his tracks. He had never seen her like this; so calm, so confident, so....sexy. She had him wrapped around her finger; he returned to her and covered her up to her chin. He had to cover up her body.

He was surprised when she clutched collar and pulled him to her. She moved her lips along his jaw line towards his ear, sending chills threw his body, "Do you want to keep me company?"

Derek couldn't take it anymore, he was breathing harder now, almost panting. He looked in her eyes with lust and began to reach up to touch her face. He stopped himself.

"No, Casey. Go to sleep" he said ripping her hand off his collar and almost running out of her room.

Casey felt humilated. She threw herself at him and he was disgusted. She cried herself to sleep that night embarrassed and heart broken.

Chapter 5: The Hangover

Casey woke up the next day in the afternoon. She could hear her family busy downstairs and the noise gave her a headache.

"Hangover cure, my ass" she said out loud, her head still fuzzy from the alcohol she had consumed the night before. She was beginning to piece together the memory of what had happened last night when her cell phone wrang.

"What happened to you?!"Casey heard Emily yell when she picked up the phone.

"Uh! Too loud Em, please talk softly, my head feels like someone hit me with a hammer.

"Hungover?" Emily replied, mercifully quieter than before," You should have had something to eat and some water before bed, it's the best way to avoid a hang over. I could have told you that if....."

Casey tuned Emily out as she remembered what had happened the night before. Derek helping her up the stairs, Derek giving her the water and donut and her botched seduction.

"Oh My GOD!" Casey yelled into the phone as she realized what had happened.

"Don't worry I didn't go home with the guy or anything" Emily said still talking on the other end of the line.

"Uh, right. That's ok, I'm not worried. Um... good for you....that's good"Casey stammered trying to cover up the fact that she had been ignoring Emily.

"You are hung over!" Emily laughed oblivious to what Casey was really thinking, "So how did you get home last night?"

"I walked and then... I don't really remember" she said remembering that she had to avoid telling Emily anything about Derek.

"Oh, I am so sorry that you walked. I wish that I could of found you but you kind of disappeared after we saw Derek grinding with Kendra"

"Oh yeah, I was there for a while but I got sick so...." Casey said sounding a little sad.

"No worries," Emily interrupted "I gotta go though, my mom is calling me"

The girls hung up and Casey dove, face first, into her pillow. She thanked God that Emily had not talked anymore about Derek....

"Crap! Derek. I can't see him," Casey wondered out loud springing up from her pillow.

Just then she heard Lizzie knocking, "Casey are you ok?"

"Yup, Liz come in"

"So, I thought you were sleeping at Emily's last night?" Liz said sitting on Casey's bed.

"I was, but I felt sick so I wanted my bed, you know how it is." another lie but Casey thought it was a good one.

"No, I don't think I know "how it is". What happened Casey, you look kind of....hung over". Lizzie said more intuitive than Casey had hoped. Lizzie didn't look mad just concerned so Casey told her the truth.

"I am hungover!" Casey admitted, shame faced, "Emily took me to this club last night, I know that I shouldn't have gone but I did and I drank and I don't normally drink and know I should be a better role model for you and...."

"It's okay," Lizzie said gently, "I know you are a good person and I'm old enough now to know that one night of drinking doesn't make you a criminal" The girls laughed together. Casey was so proud of Lizzie for having such a good head on her shoulders. She was growing up fast but Casey was thankful that she had a good friend in her sister.

"Derek is way worse than you are. He's been a grump all day, not talking to anyone and being a total pain!" Lizzie paused for a moment as she noticed Casey turn away, "Did you hang out with him and Kendra last night?"

Casey hesitated before she said anything. She was filled with guilt and embarrassment and she had no one to tell; so she decided to tell Lizzie everything.

"Something awful happened last night, not like criminal awful, but like embarrassing, never going downstairs, move away and die awful" Casey said and went on to tell her attentive sister everything. "and the worst part is" she concluded "that I realized that I like him... a lot. I like his stupid face and his stupid hair and the stupid way he fights with me and than does the sweetest thing to make everything better! HE"S MY STEPBROTHER! I can't believe I like him. I'm awful".

To Casey's surprise Liz laughed a little, "You really didn't notice that you liked him? With all the flirting and the pushing and the fighting!"

"You and Edwin fight!" she answered "but you are not an awful person who gets inappropriate pervy crushes on her stepbrother.

"The way me and Edwin fight is completely different than you and Derek. There is nothing wrong with you liking him, it's not like you've ever acted like brother and sister before"

Casey felt a little better after finding that she had Lizzie's full support,"Can you do me a favor?"

"Do you want me to tell everyone your sick so you can avoid Derek?"

"Yes please" Casey begged "And could you keep this all on the "down low" " Casey added the air quotes making Lizzie laugh at her dorky sister.

"You can count on me but, you never know, Derek might come in here to talk to you.." Lizzie said with a smile. Casey smiled back hoping that Lizzie was right.

But she wasn't; Derek didn't say a word to her the whole day.