A/N: The final chapter. It was originally going to be an epilogue, but I left too much of the plot to be finished up. So now--no epilogue, lol. Thanks to all my readers and reviewers. :) I had a lot of fun writing this story.

Disclaimer: I own neither Life with Derek or the song Drink, Swear, Steal, and Lie, which is quoted (with a few minor changes) in this chapter and is the title of the story.

Casey sat in front of Derek silently for a few minutes, watching him as he massaged his temples lightly. Finally, he could take the quiet no more, and he looked up at her.

"Are you going to tell me why I'm in trouble?" he asked, raising his eyebrows.

Casey smirked, crossing one leg over the other and drawing attention to the way her skirt was riding up her thighs… Derek felt his mouth go dry and he forced his eyes to focus on her face. "No," she said when he looked at her. "You're going to tell me why you are in trouble."

Derek's face paled, and he quickly started searching for the least offensive of the things he had done. "Uhm," he said, stalling for time as Casey raised her brows. "You mean how I paid Edwin to tell Dad and Nora you were hungover?"

Casey carefully kept her surprise from her face, and shook her head. "Not that," she said, pretending she had known about it all along.

"Then you mean about how I bribed Marti into catching you swearing?" he asked, getting desperate. These were the lightest of his latest crimes—if she meant one of the others, he was doomed.

Casey pursed her lips, getting angrier as she realized that all the time she had spent grounded had been thanks to Derek. She shook her head, "no. Not that either." She had no intention of letting him off the hook, and she was finding out some very interesting things.

"So you know I told Lizzie who stole her soccer ball?"

She nodded. "Yes, I know," she lied. "But that's not why you're in trouble." She was uncomfortable with the lie but shrugged it off. After all, even though she hadn't known, she wasn't at all surprised.

"Ah. Obviously you're mad at me because I promised whoever could catch you in a lie a ride to school in the Prince… But no one caught you, so why are you mad about that?" he asked, confused.

She shook her head. "I'm not mad about any of these things, Derek. I should have known you would do all of this—you are always concerned with swindling other peoples' money."

Derek sprang to his feet and started pacing back and forth. "Look, Casey—I wasn't doing it for the money. Okay, well yeah. At first it was just for the money. But after I started hanging out with you and talking to you, and especially after I stole your diary… I just wanted you to figure out that Gary is bad for you. He is, Casey. Look how much he's made you change! He wants you to sneak around and lie for him. A good guy wouldn't make you do that. The right guy would change for you."

"Oh yeah, Derek?" Casey asked, standing up and poking him in the chest. "What else do you know about Gary? You've never even met him!"

"I know he's cheating on you," Derek snapped, shoving her hand away.

Casey pushed him back down into his chair. "Yes. You do. You know he was cheating on me. But did you tell me?"

Derek gaped at her, mouth hanging open and eyes wide. "That's why you are mad at me? Because I didn't tell you your boyfriend was cheating on you?"

"Wouldn't you be mad if the situation was reversed?" she demaned.

"Look, Casey," Derek stood and stepped closer to her. "I didn't tell you because I didn't know how. I'm just the prankster, the liar. I didn't know if you would believe me, and I didn't want you to think that I was just trying to break you and Gary up." He put his arms around her waist and gave her a tight hug.

Casey leaned against his chest for a few minutes before pulling away. "But that still doesn't excuse all of the stuff you did! Derek, I was grounded for ever because of you."

Derek laughed. "I was really just doing it for your sake, Casey."

"How?" she asked suspiciously.

"I was trying to make you understand that you're not made for this. It's simply not possible for Casey McDonald to tell lies, to hide a hangover, or to steal. It's not who you are."

She raised her eyebrows. "You left out swear."

"Well, you're actually really good at the swearing part…." He backed away as he said it, raising his hands in a gesture of surrender before she could even try to hit him.

She shrugged, and nodded at him. "You're right. I've learned all of your lessons. I've done all the homework. But it's not me. I don't want to be you."

Derek winced. "There's nothing wrong with me! And—wait. You did all the homework? Even the lying part?"

Casey sat down on the bed, tugging on Derek's hand until he sat beside her. "Yeah. I even lied."

"But no one caught you," he argued, reclining back onto the bed.

"I didn't lie to anyone in the house."

"Gary?"

Casey nodded. "I broke up with him. I suspected he was cheating on me, and I didn't want to be the person he wanted me to be."

Derek smiled, reaching out to brush the hair out of her face so he could see her eyes. "I'm glad, Case."

She smiled too, laying down beside him and looking up at him.

"So…" he said after a few seconds of silence. "What was the lie?"

Casey winced. "Uhm… I just told him… that…" Her words trailed off as she tried to think of another lie—this one to keep Derek from finding out the truth.

Derek just laughed. "Don't even try to lie to me. You know it won't work."

She sighed, looking away and staring at the ceiling. "He accused me of being in love with you."

Derek reached over and lightly grasped her chin, tilting her face up so she was looking at him. "Okay, that's what he said. But what was the lie that you told?" He held his breath, hoping…

"I told him I wasn't," she muttered. Her face turned bright red and she tried to look away, but Derek tightened his grip on her face as he leaned down and kissed her.

It was slow, it was fast. It was hard, it was sweet. It was everything a kiss ever was, ever could be, and ever would be.

Finally after seconds—minutes, hours—Derek pulled away, with a big grin on his face. "You know, Casey…" he said. "Teaching you all these lessons has made me realize that I don't want to keep doing these things either. The only times I want to drink, swear, steal, or lie are when I'm with you."

Casey's brows furrowed in confusion. "Huh?"

Derek blushed, shaking his head. "Never mind, it's corny."

She leaned forward and kissed him lightly. "Please, tell me?"

He sighed, looking away. "I want to drink from your loving cup, swear to never give you up. I want to steal all your kisses underneath the moon. I want to lie there, next to you… Look at what you've made me do. Casey…. You're the reason why I'll drink, swear, steal, and lie."

She smiled at him. "That was corny."

"Hey," he said, tickling her ribs. "You're supposed to compliment it, not insult it!"

She grabbed his wrists to make him stop tickling her and leaned forward to kiss him again. "It was extremely sweet and very romantic. And… Corny."

He rolled his eyes and scooted down a bit on the bed, laying his head on her shoulder and drawing random designs on her stomach.

"Derek?"

"Yeah, Casey?"

"Are you really going to quit all that stuff?"

He snorted. "No."

"Der-ek!" She smacked him lightly on the top of his head.

He sat up a bit on his elbows, looking her in the eyes. "Look, Case—I'll do them less, okay? I can't just quit altogether. It's not who I am. And you know you like me for who I am." He winked at her, flashing her his famous Venturi smirk.

She mimicked his smirk. "Yeah. I do."

From that moment on, Casey McDonald became less of a prude, and Derek Venturi became less of a bad boy.

-Fin-