A/N: Wanted to get this out yesterday, but all evidence to the contrary aside, I kinda do have a life, so Happy Day after Valentine's Day!

Dedicated to EscapeSomeday, who recently reviewed pretty much all my LWD fics, favorited the ones she didn't, and inspired me to get back into this wonderful fandom.

Chocolate

Derek was on his way out the apartment door, shrugging on his new leather jacket (courtesy of Casey on his birthday) and thinking about the lovely Tanya, whom he was going to be meeting at a local restaurant in half an hour, when he spotted his stepsister-slash-roommate moving around in the living room. As soon as he noticed she was decked out in sweatpants and a tank-top, hair pulled back into a messy bun, and not clad for a Valentine's Night out on the town with some random dude, he immediately went into pesky stepbrother mode.

"No hot date tonight?" he questioned tauntingly, strolling into her line of sight.

"Nope," Casey responded like it didn't matter and busied herself with fluffing the pillows on their couch.

Derek wasn't about to give up that easily; he still had some time to kill before his rendezvous. "Then shouldn't you be out with the Spasey Squad?" he pressed, alluding to the group of somewhat ditzy girls Casey often brought back to the apartment for movie nights and gossip.

Unfortunately for Derek's intentions of viewing her frustration, Casey had her back to him as she said, "They all have guys taking them someplace nice." She turned toward the nearest end table, grabbed the box of chocolates sitting there, and plopped unceremoniously onto the sofa.

"And they just abandoned their leader?" Derek quipped, noting that the chocolates were some of the ones he'd gotten as presents from eager and obsessed females.

Casey looked at him just briefly, a glint of hurt shining in her eyes until she returned her gaze to the assortment of candy. "I'm fine on my own . . . How about you? Going out to meet one of your girls?" she redirected smoothly.

But, of course, the damage caused by that pained pair of blue was done. Before Derek knew what he was saying, he had already spewed out the lie, "Nah, you know me--commitment issues. I'm going out for a drink with the guys." He watched Casey's lips close around a cherry cordial, and his eye twitched in a physiological attempt to pull him from the resulting near-trance. "So, uh . . . You're really just gonna stay here all night?"

"Yeah." Casey chewed and nodded. "Why?"

"Well, I mean . . ." Derek struggled to find the words. "Won't you be . . . bored?"

Casey rolled her eyes defensively. "No. There's a romantic comedy marathon on T.V. that I'm really looking forward to."

Derek snorted. "Right." The thought of his poor stepsister huddling on the couch, all by her lonesome, in front of a slew of chick flicks that were just going to make her bitterer about how nobody asked her out, went a long way toward making Derek feel like punching every guy who saw her and didn't want to date her. He was incapable of imagining what they could have possibly been thinking that would distract them from this magnificent, gorgeous, witty--

Unlike Derek, they didn't have the obvious social taboos to keep their longing at bay.

"The guys probably wouldn't mind if you came drinking with us," he tried, forgetting that his earlier statement had been a lie.

"Ugh. I think I'll refrain from exposure to your drunken hockey buddies, thanks," Casey scoffed, nose wrinkled adorably as she pictured the downhill slope of the evening that would accompany rising blood-alcohol levels. "I'm definitely not that desperate to get out, even if it is Valentine's Day."

"Okay then," Derek accepted huffily, half-pretending to be offended and exiting into the entrance hall. He frowned at his dilemma, wishing there was something he could do, short of asking Casey out himself, which was really not an option. Tamara was gonna be thinking he'd stood her up if he postponed his departure any longer, but in light of the idea that dawned on him as his hand brushed the doorknob (and the fact that he could barely remember the blonde tramp's name, anyway), he didn't care.

He pulled off his coat and re-hung it in the closet, mentally insisting that his newly formed plan was the only suitable solution.

"Der-ek!" Casey squealed as her stepbrother crash-landed almost on top of her on the sofa, grinning like a madman. "What're you doing?" she demanded and glanced at the television, which she had switched on in Derek's short absence, as if the actors on-screen might know what was in his nutty head.

"You're not eating my hard-earned chocolate all by yourself, Princess," Derek teased, reaching over into the box and pulling out the nearest confection. "Don't wantcha getting fat and doubling our grocery bills."

"Oh, gimme a break," Casey rejoined dryly, though her expression was as playful as the almost-smile tugging at her mouth. "Like flirting your way into girls' pants is hard."

"You have no idea how hard it is," Derek joked, wriggling his eyebrows suggestively.

"Ew! Der-ek!" Casey clocked him firmly on the shoulder as punishment, even though she was obviously holding back a feminist values-crushing chuckle.

"So." Pleased and smiling, Derek snuggled further into the cushions, just as close to Casey as was acceptable. "What're we watching?"

Richard Gere's rodent-like features panned into view on the T.V., and Casey informed, "Looks like Pretty Woman," smirking at the horror that overtook Derek's face.

"Man, I must really love you," he muttered disbelievingly, and while he meant the words as he said them, Casey didn't need to know the whole truth; he saved himself with a heart-shaped chocolate. "Be mine?" he proposed, holding the candy out to her good-humoredly.

Casey blinked at him at first but, after falling into the rhythm of their banter, took it from his palm with an exaggeratedly flattered flutter of the eyelashes. "Really? Me?"

Derek moved his head in the affirmative, well-aware and relieved that Casey had no idea how serious he would have loved to be.

"Well, okay--but just until we finish this box." Casey flashed her teeth winningly.

"Absolutely," Derek agreed and spent the evening fake-celebrating this holiday with the person he adored the most. He didn't even answer his phone when Tasha called.