A/N: For those who have not see the "Crushing the Coach" episode, and therefore do not know who Scott is, Scott is Lizzie's soccer coach and first crush, not a figment of my imagination or an especially important plot point. He hits on Casey, and ends up taking her out on two dates. After the first, he admits to Derek that he is coaching the soccer team so he can date the team's older sisters; Casey is the fourth, and he is dating all simultaneously. Derek goes briefly insane, as he feels that he needs to intervene but does not want to be caught doing the right thing. Aided by Edwin, he confronts Scott when he brings Casey home from the second date by inviting all three other sisters over after telling them the truth about Scott. Scott ends up humiliated, and Derek ends up having done the right thing and on a date with one of the other soccer sisters. Lizzie does not know this about Scott because Derek, Casey, and Edwin all agreed that it was best not to tell her, so she could remember her first crush fondly.

Don't Taunt the Tiger

Casey hated to have to do this. She really hated having to do this. Emily had had a point, though; if anyone was worshipped in their school, it was Derek. And if anyone was a womanizing pig, it was Derek. And if anyone knew why every guy in the school seemed to develop an allergy to her whenever she started to befriend them, it would be Derek.

It would be Derek. She would rather have asked Marti for help.

It had to be Derek.

All through dinner, Edwin had been smiling tightly at everyone who even glanced his way. When he scurried past her in the hallway toward his room, she was suddenly inclined to ask what on earth Derek was plotting that was making Edwin do that.

But no. She was on a mission. And anyway, it wasn't her business. After that shampoo incident, she could at least expect to be free of Derek-planned pranks for another day or two. Time was that Derek's pranks never stopped, but since she and Sam had dated, Derek's pranks had started to tone down from hourly sessions of torture to semi-daily demonstrations of dominance.

Not that he was dominant. Usually. She knew that he would see this as a victory, but there just wasn't any way around it. She'd asked Sam, but he had given a vague and noncommittal answer, and told her that he really didn't know. And she couldn't push it further because, hello? Ex-boyfriend. That meant that relationship talk had to be kept at an absolute minimum.

So that left Derek.

She knocked at the door. His voice—cocky, confident, and obnoxious—called out, "Enter!"

She opened the door and stepped inside. Gathering all her courage (and abandoning all her pride), she closed the door behind her.

Derek looked up at her from his bed. "You're not Edwin."

Casey gave him a look that she hoped would scream mockery and stupidity right in his ears. "Yes, I know."

He sighed. "You know, you give the kid an errand. Make him feel part of something. Then he takes hours to find a game plan. I should fire him." He gave her a falsely melancholy look. "But you don't want to hear about Ed and my games. So out with it. What do you want?"

She twirled a bit of hair on her finger, mulling the words over in her head. He rolled his eyes, got up, and started pushing her toward the door. She panicked; she didn't think that, once expelled, she would have the courage to come back here again on this mission.

"Derek, stop!" Her voice was a little shrill.

He stopped, although he stopped long enough after she'd told him to that she knew he'd pushed her further simply to prove that could. Then he retreated back to the bed, and flopped down again. "So, what do you need my help with today?"

"Why aren't any guys asking me out on dates?" She felt out of place and vulnerable, and she knew that he was about to laugh.

He did. "If I tell you, what will you give me in return?"

"Huh?" Derek was so selfish sometimes. Life in this house would run much smoother if Derek did something once in a while to benefit someone in the house without needing to get something back.

"Casey. Casey, Casey, Casey." He smirked at her. "You don't really think I'm just going to help you out of the goodness of my heart, do you?"

"No, that would be the human thing to do," she snapped.

He put a hand over his heart. "I'm wounded." She tapped her foot. He spread his hands out. "I can't help you unless you make me some kind of deal."

"I'll do the dishes for you tomorrow night."

Derek let out a laugh. "Nice try. Tomorrow's your turn."

Of all the times for Derek to start paying attention to the schedules, she thought. An idea occurred to her, and she said, hesitantly, "I suppose I can put off doing my paper and help you study for the history test."

She'd caught him off-guard, and she could tell that he was very, very confused. "Okay. Casey. One, why do I care how I do, and two, why would I start studying now? It's not until some time next week. Or the week after." He shrugged. "You're really losing it."

Casey forced an incredulous look onto her face. Life with Derek had taught her that lies could be necessary for a peaceful household. "Derek, that test is tomorrow."

He shook his head. "Case, if it was, you wouldn't have had Emily over here for a gossip session. And, by the way, next time keep it down. The rest of us don't care that you can't get a date."

Apparently life with Derek hadn't taught her how to lie well.

"Please?" Grovelling for Derek was at the top of her list of things she never wanted to do, but she felt desperate. And she felt the words slipping out of her mouth against her own volition. "Derek, I'm your sister."

He gave what almost looked like an involuntary spasm. "Step-sister. Step."

"Whatever."

Derek appeared to be considering it. "I'm not doing this out of the goodness of my heart," he warned. "You'll have to pay me back, sometime. Somehow." He swung his legs over, and settled his feet on the ground. He leaned forward. "Now, Casey. Part of the problem is that, well, people saw your relationship with Sam. You were such a pain."

"Did Sam tell you that?" Casey was taken aback. That didn't sound like Sam.

Derek laughed. "Casey, he didn't have to. Come on. 'Sam,'" he said, putting on what was obviously a supposed to be a bad imitation of her voice. "'Do you want to do something after school today?' 'Sure, Casey,'" he answered, deepening his voice. "'I'd love to.' 'Well,'" Derek pitched his voice high again. "'Well, I was thinking maybe a movie.' 'Sure. What do you want to see?' 'God, Sam, don't you care?' 'If you're happy, I'm happy.' 'Why, because I'm just a wreck when I'm not happy? Because I'm too annoying when I'm unhappy?' 'Casey, that's not what I said.'" Derek now added a note of hysteria to his voice. "'No, just what you meant!' And then," he said, "you stomp away."

She blushed. "Is that all?"

"There are other things that not everyone is as tolerant of as I am." She wanted to smack him. "I'm sure you're familiar with them." He ticked them off on his fingers. "Klutzilla. Grade grubber. Control freak."

"Derek, I get it!" she shrieked. "What can I do?"

He sighed. "I suppose I might be able to put in a good word for you with someone…"

She felt a thrill of unease settle in her stomach, and tried to ignore it. "Okay."

"What do you say?" he prodded.

Casey sighed. "Thank you, Derek."

He nodded, placated. "Good. Now go."

She wrinkled her nose. She didn't want to follow his orders, and she didn't like the way that he assumed that she would. But at the same time… insulting him right now might not help her. So she left, feeling strange and bothered.

And as she tended to do when she felt strange and bothered, she barged in Lizzie's room. "Lizzie, I just did something really stupid."

"What this time?" Lizzie sounded exasperated. Casey assumed it wasn't important, and began to spill.

"I just made a deal with Derek."

"No!"

"Yes," Casey confirmed miserably. "I don't know what got into me. I'm just so tired of not having anyone interested in dating me, and everyone likes Derek, and…" She sunk into a chair and put her head in her hands. "Liz, why did I do that?"

"That was really dumb."

"Yes, I know, Lizzie. What do I do about it?"

She could see Lizzie thinking. "So, let me make sure I've got this straight. You're having dating problems, so you asked Derek to help."

"Was that stupid?"

"Well…" her voice trailed off. "Um. Maybe not?"

"What do you mean, maybe? Don't you mean definitely?"

"Casey!" Casey looked up. "Snap out of it!" She got up and started pacing. "Look, Case, I don't think that Derek is incapable of doing good things for you. They just usually come with strings attached. And," she pointed out, "Derek has always acted odd where you and dating are concerned."

"No he hasn't." Casey thought about it. "He has?"

"Well, with Sam. Okay, fine, he didn't want you stealing his best friend. But I'm not sure that was all of it."

"Then what was it?"

"I think he was uncomfortable with the idea of watching his best friend with you, because it turned you into a girlfriend."

"Derek doesn't want to date me!" Casey said violently, horrified.

"Of course he doesn't," Lizzie said, looking equally horrified. "But Edwin and I think that he doesn't know where you fit in here, yet, and that he doesn't want any more complications."

"You and Edwin have been talking about me?" Casey felt, very suddenly, very strange.

"Research," Lizzie said dismissively. "The point is, he doesn't want a new variable added to you yet. I still think that Derek somehow got rid of Scott, and he somehow convinced Scott to lie about it."

"And he sabotaged the blind dates, too!" Casey exclaimed. Aha.

"Exactly."

Casey felt a brief touch of success, and then realized that it got her nowhere. "So what does that mean?"

Lizzie smiled. "That teenagers are weird, and that there is research to be done."