Chapter 1: Best Summer Ever!

Disclaimer: I don't own Life with Derek or any of these characters.

Author's Note: This chapter has been updated since it was first uploaded. Thank you to everyone who has stuck with this story from the beginning. As for new readers, I hope you enjoy the ride! Reviews are always welcome, they help me a lot in figuring out fun twists moving forward. I really enjoy hearing about what you expected coming in to the chapter, what surprised you, and what you predict moving forward. If you enjoy the story, please consider crediting me by giving this story a fave. Thanks, I appreciate it! I'm relatively new to this fandom, and it's been so fun writing these characters and their complicated relationship.

"Isn't this nice?" Casey chirped from the front seat of Truman's car, "All of us hanging out together!"

"It's not so much hanging out." Derek countered, "More like…going to the same location at the same time."

Derek had been tightly stuffed in the back seat with Emily and Sam. He always rode shot-gun, but not this time. Truman had invited Casey up to the front.

Hanging out with Casey and her boyfriend…Derek almost scoffed out loud at the idea, but he elected to roll his eyes instead. He crossed his arms and shifted uncomfortably into the leather seats of the hot car. He was incredibly aware of Emily's burning hand on his knee, and it only made him more uncomfortable.

"You might as well get used to it Derek." Casey said smugly. "Now that you're dating my best friend, you'll never be able to get rid of me!"

Emily squeezed Derek's knee in acknowledgement, and he offered a weak smile in return.

"Great." Derek mumbled.

"Don't worry, Derek." Emily said reassuringly, giving him another squeeze. "This is going to be the summer of our lives! Come on! We're on our way to a party, not a funeral."

Derek fake-chuckled at Emily's lame attempt at hyping him up for what was sure to be the weirdest party he would ever attend. He couldn't stand the party host…Truman. Derek had always been a little skeptical of the guy; there was something off about him. Truman barged into his life as a rival, upsetting the school order by trying to sell himself as the new resident womanizer. It didn't help that Truman had eyes for Derek's keener step-sister, Casey. While Casey had been able to forgive Truman for his questionable ways, Derek remained suspicious. He was currently giving Truman one last chance for Casey's sake, but he didn't trust him. Truthfully, Derek didn't know why he cared about Casey's stupid boyfriend…she could make her own terrible decisions. But, like a sucker, Derek cared anyway.

He laughed doubtfully. "I don't know—"

Sam joined in "Yeah, come on D!" He smiled encouragingly. "Lighten up, man."

Derek painfully swallowed his pride. His best friend was right. He didn't want to be a buzzkill.

"Fine." Derek held up his hands in defeat. "I guess I can make the best of it." Emily jumped around excitedly in her seat and tightly squeezed Derek's knee.

"Well, I know I will be making the best of these next few months!" Casey gushed. "It's my last summer before I go off to University and I want everything to be perfect! I am so excited, I have everything planned."

"Oh, we will absolutely be making the best of this summer." Casey's slime-ball boyfriend said, winking at her deliberately as though he was trying to let everyone in on some secret joke. It seemed suggestive of something. Even though Derek couldn't see Casey's face, he could feel her blushing in the seat in front of him.

Any lingering hope Derek had for having a good time went out the window. He watched the houses on the street fly by, his mind wandering while the rest of the crew chattered excitedly about the graduation party. He wanted to say something sarcastic and cutting to Truman to show how annoyed he was with the whole situation. But, Derek knew it would just start a fight with Casey. The fighting wasn't really the problem though…Derek loved fighting with Casey (it was fun). But, he knew that everyone in the car would take her side and the drive would become much more annoying.

As they drove on, Derek started noticing the houses progressively becoming larger…and more expensive looking.

"That's me up there." Truman pointed out his driver's side window.

"Oh my gosh!" Casey exclaimed. "That's where you live?"

"You've never been to Truman's house before Casey?" Emily laughed "You've been dating for like—Oh my god! Truman, your house is huge!"

"Whoa," Sam agreed.

Leaning forward to see past Truman, Derek had to admit that Emily was right. The house was big. It was almost comically enormous…perched upon a tall hill away from the surrounding properties.

Of course, this guy would be loaded. Derek fought the urge to groan in annoyance.

The car erupted into giggles. Derek would normally love the sound of giggling girls. Music to his ears! However, he was used to the sound being directed solely at himself. He hated how Truman seemed to be loving every bit of it.

"I didn't know you were rich Truman!" Casey said, her tone a mix of awe and light-accusation, "Why didn't you tell me?"

"Please." Truman said with a cocky grin. "It's my parents, not me!" The girls once again burst into giggles.

This is torture.

When Truman stopped the car and killed the engine, Derek couldn't help but breathe a sigh of relief. He needed to get out of that damn car. Stupid little German sports car with no room in the back seat! He would much rather be at home in his recliner, playing Babe Raider.

Truman opened his front door dramatically, as though he were Willy-fucking-Wonka. Casey and Emily held on to each other and ran inside, continually giggling like its all they knew how to do anymore. Derek hung back with Sam and they slowly made their way into the lavish entrance hall.

The house was even more impressive inside. "Food and drinks are this way." Truman announced, guiding them all forward. "People will be here any minute, so let's have a toast." He passed around champagne glasses and popped open a bottle as if it were an incredible feat.

Sam mustered a small "Woo!"

The girls jumped around, squealing enthusiastically, sufficiently impressed. Derek wasn't sure how Casey could be so oblivious. He could see right through Truman…so why couldn't she? Every time Derek saw them with each other, he regretted getting them back together. It was too late though. It would be stupid of him to try and do anything about it now.

He was impatient for the party to start, so that he could avoid the happy couple. He didn't need the continuous torture of watching Casey gush over Truman's smug ass all night. He hooked his arm around Emily's waist and pulled her closer. Emily was a little shocked by the sudden embrace, but she turned her attention to him, beaming and wrapping herself around him.

Truman started to a pour a glass of champagne for Casey, while everyone (but Derek) chuckled joyously. Derek had decided he would be a good sport, and keep his mouth shut, but he simply couldn't hold it in anymore.

"Yay…" He groaned in mock-excitement. All eyes turned to him. "Three more months of this! Best summer ever…"

Truman stopped pouring. Everyone's eyes darted to Casey, whose own glare was locked on Derek like a heat-seeking missile.

"Der-ek!" She snapped. Classic Casey. Derek felt Emily slip out from his arm, as everyone wisely distanced themselves from the quarreling duo. "Need I remind you that you wouldn't have even been invited if you weren't with Emily? I'm not going to let you ruin my night!" They stared each other down.

Derek knew his mere presence could ruin Casey's night. The party seemed to mean a lot to her for some odd (probably dramatic) reason. He gave in and rolled his eyes. After all, he didn't want to be a buzzkill.

Casey seemed satisfied with his yield. "Let's have a toast!" She exclaimed. She grabbed the bottle of champagne and subsequently poured it into the empty glasses everyone had been awkwardly holding on to.

"To the best summer ever!" She cheered.

"To the best summer ever!" The group shouted, preparing to clink glasses. Casey shot a disapproving look at Derek, who hadn't said anything. The group waited with her.

"To the best summer ever…" Derek conceded, clinking Casey's glass as a token of good faith.

Clink, clink…clink. Derek downed the hatch. Casey gingerly sipped her champagne with a bright smile. She looked so happy and relaxed. Derek became aware of the stiffness in his body and allowed himself to relax too. If Casey of all people could have fun tonight, so could he.