A/N: This fic was born partially from my overwhelming joy after seeing the episode "Tuesday Afternoon Fever." If you haven't seen it yet, you're missing out. :) No spoilers, I promise.

Essentially, this story is just a dash of Truman-bashing and a healthy dose of fluffy, Dasey goodness.

Chapter 1

Emily

Casey gasped and took a deep breath, obviously trying to calm herself down. "The test dates for senior year are up!" she squealed to her best friend, jumping up and down with joy.

"Great," said Emily, frowning, "thanks for ruining a perfectly decent day." But she couldn't help grinning at the resurgence of scholarly enthusiasm in Casey's happiness.

"What? '…ruining a perfectly decent day'?" said Casey, cocking her head in confusion. "But this is a good thing!"

Rolling her eyes, Emily replied, "Riiiiight…"

A figure appeared at their sides, and Emily's guydar blared warnings in her head. "Squealing over me, Case?" a familiar voice asked in Casey's ear, before nipping at her earlobe. Emily groaned to herself. Casey laughed and batted her boyfriend away.

"Dream on, Truman," she said, grinning. "You're almost as conceited as my step-brother." Much more, actually, Emily thought.

"But much more attractive," he chuckled, flashing the girls a grin.

Emily rolled her eyes. "Actually, Truman, according to my research data, the female population of JSTH begs to differ. Overwhelming consensus is that Derek is far better looking." She paused and sneered (unable to help herself), "The male population, however, finds you quite appealing…"

"That's disgusting," cried Truman. He leaned over to kiss Casey's lips, lingering far too long for Emily's tastes. Maybe he's trying to assert his so-called manliness or something, Emily thought. She grabbed her friend's sleeve and tugged her away.

"Later, Truman," she said over her shoulder, pushing Casey into the girl's bathroom. "So," she asked her best friend once they were safely inside, "when are you going to dump Truman? He's no good for you, Casey. You deserve so much better."

"Well, Truman's not so bad," Casey said, not meeting Emily's eyes.

"Uh, yeah, he really is."

"It was sweet of him to get me back into my fencing class for gym. And put up with my 'perfect' date prank."

"Whatever, Casey," Emily declared, "I think the bell's about to ring anyway. See you around." She gave her friend a brief hug and left the bathroom, shaking her head. I've got to do something about this, she thought. And fast.

Casey

As Emily left the bathroom, Casey turned to face herself in the mirror. She looked like Casey. Wasn't she still herself? Truman was… well, he was Truman. She knew that she'd made a mistake in dating Max (she'd lost her sense of self), but Truman just encouraged her fiery personality and challenged her wit. Who else did that sort of thing?

Suddenly, she felt someone bump into her from behind. Spinning around, Casey felt her eyes widen in annoyance at discovering who it was. "Derek!" she screeched, shoving him away from her. He'd been playing catch in the hallways again, and had bumped into her… again. This sort of thing always happened.

"Oops, didn't see you there," he said, shooting her a grin. Casey pushed down the flare of excitement that formed in her chest at the thought that his smile was directed at her. She hated Derek. She couldn't believe that the girls at her High school had deemed him more attractive than Truman. Pah! Derek may have better hair and a sexier smirk—wait, no he didn't. Truman was much better looking. Of course he was. He had to be. Casey didn't find Derek attractive at all. He was her step-brother after all.

"Looks like you're the one who's become the klutzilla of the family," Casey snapped at him, giving him a brief shove away from her.

Derek just laughed. "Gee, sis, are you sure you aren't just confusing your fantasies with reality? Doesn't that happen a lot when I'm involved?" He tossed the ball at her head, and the foamy surface bounced against her forehead.

"De-REK!" He was outright guffawing now, and Ralph had a smile on his face. "You are NOT in my fantasies! And stop calling me 'sis.' It's an insult to my genetic make-up."

"Well, if your genetic make-up is anything like the crap you put on your face, then I'd say that my being in your family is actually beneficial to your genes."

Casey huffed in exasperation and gave him a huge shove away. A group of freshman had gathered around them, clearly looking confused and uncertain at what was going on. One girl had stars in her eyes as she gazed at Derek, a fact that just made Casey even angrier.

"Shut up, Derek, and go back to the pigsty where you belong," Casey snapped, crossing her arms.

Tossing the ball up and down, Derek's mouth twisted up in a mischievous smirk. He looked over and winked at the star-struck freshman girl, then aimed the ball at Casey's chest. It hit her and bounced away, falling to the ground at Derek's feet.

"Right on, D!" Ralph cried in congratulations, high-fiving his friend. Derek returned the high-five and patted Casey's arm before waltzing away.

Casey stood fuming at her step-brother as the crowd of freshman started to disperse. A short, brown-haired girl approached her and asked boldly, "Who was that?" It was the girl who'd been gazing at Derek with adoration.

"A waking nightmare," Casey replied, not tearing her eyes away from the retreating form of Derek.

"Is he your ex?" the freshman chirped. "Is he single now?"

At this, Casey looked down at the girl. She was pretty and had a scattering of freckles across her nose. "He's my step-brother, and don't even bother."

"Ohhh," the girl replied, raising an eyebrow and grinning as though sharing a personal joke with herself. "I get it."

"You get what?" Casey demanded, feeling her heartbeat quicken for some reason.

"You're carrying the torch for him, huh? But he doesn't know it? That's the rumor going around school, anyway."

"What?!" gasped Casey, grabbing onto her locker to support herself. "That's just—how could I—I have a boyfriend, you know!"

"Truman French?" the small brunette asked, raising the other eyebrow. "Last time I checked, he was just a less-attractive, more obnoxious version of Derek Venturi."

"Why, you little—" But before Casey could continue, the bell rang and everyone bustled to get to class. The freshman girl disappeared into the crowd and Casey sighed, wishing her pulse would slow to a more normal pace.

Derek

Derek found himself whistling as he entered the front door of his house. It had been a good day. Despite the freezing wind and the thin layer of snow coating the ground, a smile graced his lips. He'd out-witted Casey (again), he'd escaped being caught playing catch in the hallway, and he'd managed to get out of doing at least two assignments (thanks to his skills of persuasion). But best of all was the rumor that he'd heard going around school. It was a rumor about Casey and her apparent "infatuation" with him. Although he was sure it was false, it still offered him an incredible amount of leeway over her. The only bad part of the day had been when he'd been told that Truman wanted to have a little "chat" with him about said rumor. Great. Just the thing he wanted: a chat with Truman about Casey.

Hanging up his leather jacket, he started to smirk as he planned out when to best use the rumor against Casey. Perhaps he would exit the show with only a towel around his waist. Or maybe he could burst in on her room unannounced. If he was really evil, he could bring it up at dinner, but Derek quickly decided against that option. It might make for some serious awkwardness around the entire family.

In the end, Derek decided to let the circumstances determine when and how to best bring up the topic of her supposed "crush" on him. He wondered who'd spread the rumor in the first place. It was unlikely that it was Sam; Ralph might have had something to do with it, but that seemed unlikely as well. Maybe it was one of Casey's friends. Derek didn't know, and he didn't really care. The important thing was that there was a rumor, and that he could use it to gain leverage against Casey.

Said person finally bumbled into the house, carrying two projects that had been graded over the break along with her regular amount of school things. Derek smirked as he watched Casey stumbled over the front step; he was surprised that she hadn't tripped and fallen on her face yet.

"Derek!" she whined, her voice shrill with annoyance, "Aren't you going to offer to help me?"

He paused, as if seriously considering her question, then said, "Hmm, nope. It's much more fun to watch you struggle."

She groaned in exasperation and finally managed to set her things on the table. Brushing her hair out of her face, she pursed her lips and faced him. "Truman's coming over for dinner," she said, "So please behave tonight."

Derek rolled his eyes. "Great. And I'd considered this a good day not a moment before."

"Well, tough luck, because he's coming over whether you like it or not."

Irritated, Derek stomped up to his room and logged onto his computer, musing over the situation. As he thought, a small smirk formed on his lips. He had a plan.