It's a little late for a christmas story, I realize, but this was written for Lady Liln as part of the tweensanta fic exchange on LJ.

The prompt was as follows: A Dasey Christmas/holidays. That's all I ask, the rest is up to you--just anything to make up for A Very Derekus Christmas.

Given I've only seen about half of season four, this might be a little AU. For the most part everything's based upon various spoilers I've come across. All you really need to know is that this story is set in the post-series future. Thanks so much to mondleringmoofoot for the editing and nice comments and just generally being awesome.

I don't own these shows or these characters.

-----

On the first day after her last final she practically beats down the door to his dorm. His roommate Joe had already vacated the room (Derek's kind of thankful for this).

She pours some cold water on him. "Pack your things. I'll be back in hour so that we can drive home."

She's out the door before he can think of anything sarcastic to say.

----

She's on the war path and Derek is too exhausted from finals and her dramatics to speak to her so when she gets in the driver's seat he doesn't say much other than, "You're driving." She glares at him and he rolls his eyes and throws his stuff in the backseat.

They spend the whole car ride home in awkward silence. Derek lets her choose the music, but puts some earphones in and tries his best to listen to that instead. She's feeling particularly spiteful, so she turns it up (in the middle of "My Heart Will Go On" no less). He gives her a look, and she almost visibly withers and turns it down.

While he is pretending to be sleeping, she turns it down and picks up her phone. Derek turns his mp3 player down and quickly realizes she is talking to Truman.

All he can think is are they still pretending this is working?

---

He spends the first few hours at home making a snowman with Marti. He's partially doing it because he loves his sister (but also doesn't really mind avoiding Casey for the moment).

It gets a little too cold, so he decides to brave the potential chill inside for a cup of coffee. He runs into Casey in the doorway, they both stop, and wait for one person to say something, pointedly ignoring the mistletoe above them. (Edwin must have a girl coming over, Derek thinks.)

"Get out of my way," he finally says.

She groans in frustration (with him. just with him.) and heads out into the cold.

"Where are you going?" he shouts out after her.

"Out to see my boyfriend," she says.

He curses and slams the door shut before any more cold air can get in.

---

Casey and Truman exchange Christmas gifts. She loves the gift and they talk and laugh and make out.

She has a terrible time.

--

Derek considers sending Casey a text message making fun of Truman the douchebag.

But that seems petty. (He's still not sure how she didn't see through that stupid 6 and a 1/2 thing. A guy would have to be blind to rate her lower than a nine.)

--

When she comes home she puts on a fake smile that Derek (hopes) he is seeing through.

They run into each other outside the bathroom.

"How was your date with your not-boyfriend?"

"Derek we're only thinking about seeing other people. And even if we do, we're still going to see each other."

"First, Casey, you don't do open relationships. Second nobody every just thinks about seeing other people."

She takes a step forward and it feels like old times. "No Derek, you never just think about seeing other people."

"Truman and I do have things in common. For example we have made out with several of the same girls." He counts off on his finger, "Kendra, Vicky, you."

She huffs for a moment. "Derek, we agreed that that didn't happen."

"Actually, you agreed that it didn't happen, and while I'm sure the voices in your head count to you they don't to me."

"Well, if you don't have any problems with what happened, why don't you just go next door and tell Emily."

"Not the same thing, Case. But, since you mentioned it, at least we can realize when something's not working."

"Don't change the subject, Derek. You aren't so ready to let people know about that thing that didn't happen. So let's. drop it." She pauses for a moment, exhaling loudly as though it would cleanse her of the entire conversation. "Now, if you excuse me, I have to use the bathroom."

She slams the door shut and Derek clenches his fist.

---

At dinner George and Nora actually notice that something's up.

George approaches Derek and asks him if he and Casey are getting along at school.

Derek says, "You know Casey. She's uptight and my ability to actually enjoy life bothers her."

"Derek," George says in his best fatherly, admonishing voice.

"Look, don't worry about it. I promise to be pretend to be nice to her. So you can go tell Nora you took care of it."

George accepts this, sort of. He says something about how their old enough to work these things out on their own now. Really he's kind of just afraid to deal with it.

Derek is thankful for this. He figures saying well dad, Casey and I made out and she's trying to pretend it didn't happen might not go over so well.

---

It's three days until Christmas and Derek wonders if he should take the Christmas present back and get something that won't make her hate him even more than she already does.

---

Casey hangs out with Truman the day before Christmas Eve. He brings up seeing other people and even though she knows it will bring Derek too much satisfaction she says, "I don't think this is working," and wishes him the best as she slips out of a booth at Smelly Nellie's.

She knows Derek will find out eventually (it took Truman all of two hours to change his Facebook status to single) but she doesn't bring it up.

---

Derek thinks Facebook is kind of weird, but he still has one because he is in college and apparently they won't let you in if you don't have a profile.

That doesn't stop him from checking it over Christmas break.

He can't decide whether to go comfort her or gloat.

So he doesn't do anything (when did he turn into such a wuss, anyway?).

---

Derek's feeling extra restless at about 2:00 a.m. Christmas eve morning, so he heads down to the kitchen.

Apparently, he isn't the only restless one and he catches Casey in her pajamas eating ice cream out of the carton.

She jumps when he asks, "Don't you think it's a little cold out for ice cream, Casey?"

She groans. "What are you doing up?"

He walks the rest of the way into the kitchen and puts his hands on the island. "Not happy to see me while you satisfy your little break-up cravings?"

She sets the ice cream down. The spoon falls out of the carton, hitting the counter with a clang. "Derek, I am not in the mood for your little 'I told you so's so how about you just go pretend that you said it and I reacted. Then you can go upstairs and leave me alone."

"Obviously I don't have to say it to get you to react."

She ignores him.

He wants to walk to her side of the breakfast bar, but doesn't. "Look, I wasn't going to say I told you so." She looks at him pointedly. He concedes, "Well maybe I would have, but I would also say it's probably for the best. You are too good for him. Now you can find somebody who isn't such an asshole."

"Oh, and I suppose that's you."

He gives her a little smile. "Casey, I said somebody who wasn't an asshole."

She actually laughs at that.

"You aren't an asshole." This time he looks at her pointedly, "Well, maybe you are sometimes, but not all the time. You can actually be a decent guy every now and then."

He inspects the synthetic wood grains of the countertop, follows them as they circle around a fake knot and then fall off the edge of the counter. He looks back up when he tells her. "I feel like we've already established that."

She grabs the spoon off the counter and starts poking at the ice scream. "I know. I don't give you enough credit. "

He takes a few steps back without turning around and says "I'm used to it," before he goes back to lying awake in his bedroom.

Even though he still knows that the gift could make her hate him more he decides not to take it back.

---

Casey and Derek are actually civil the next morning, so Nora assumes George's talk did all the good and corners him with the mistletoe. He doesn't really mind so much, of course.

The family spends the morning preparing in various ways for a Christmas at home. (College tuition provided a good excuse for George and Nora to keep their Christmasing to the immediate family. They like it better that way anyway)

Derek spends part of the day in his room haphazardly wrapping gifts (Nora apparently thinks he is too old for her to do it for him and he doesn't have any money to pay Edwin). He doesn't wrap Casey's because he knows that he can't have her open it in front everybody else.

This also means that he's going to find a way to give it to her before Christmas morning, because if the gift itself might incur the wrath of Casey he can't imagine what would happen if she spent most of Christmas day thinking he didn't get her anything.

When he comes down the stairs he finds Casey covered in flour and things from making cookies with Nora. There is frosting on her face. (It's cliché, he knows, but damn her for being so adorable.) When he walks into the kitchen she smiles at him, and he wonders if she's trying to kill him.

Nora sees him and asks, "Derek will you be celebrating Christmas or Derekus this year?"

He tries not to look at Casey when he answers, "Well, I've decided that really I'm so awesome that every day is Derekus, so I might as well celebrate Christmas at least one of those days."

He desperately wants to ask Casey to talk right then, but he doesn't want to have to play 20 questions with Nora so he waits.

---

It seems like everyone is suddenly very into hanging out with Casey and after dinner Lizzie nabs her for some girl talk or something else that Derek equally wants to avoid.

Then it's suddenly time for some family bonding over board games, so Derek just decides to try to catch her when she goes to bed.

He starts to tell the family to count him out, but Marti begs, Nora gives him a look, and Casey looks at him like she is far too interested in which decision he makes.

(Seriously, when did he turn into this?)

He says, "Alright, Smarti," and takes a seat at the dining room table.

When Casey gets up to get more chips he follows her in the kitchen on the pretense of refilling his drink.

He hates doing this kind of thing, so he fills his glass, turns to look at her and says, "We need to talk," leaving the kitchen before she can respond.

----

He wants to hang out at his bedroom door waiting for Casey to come upstairs but people keep going in and out of the bathroom so he gives up and enters his room. He turns on some music, opens up a magazine and hopes that Casey shows up.

He has to wait for a bit, but she does. "That's not a dirty magazine I hope."

He rolls it up in his hand as she sits down on his bed. "Of course not. I left them all at school."

She rolls her eyes, but lets out an almost laugh. Then she pulls the magazine out of his hand and hits him with it.

Neither of them say anything for a moment. Casey has one leg dangling off the bed, the other folded in. She picks lint off the blanket, waiting for him to say something, but isn't very patient, so she starts. "Derek..." She trails off when she's not sure what to say after that.

He mocks her. "Casey."

She sighs and actually looks at him. "You wanted to talk. Let's talk."

"I just wanted to give you your Christmas present."

He gets off the bed as Casey asks, "Why can't you just give it to me tomorrow?"

He ignores her question and starts digging through his duffel bag, pulling wadded up clothes out of it and letting them fall to the floor.

"Did you fold anything you brought?"

He smiles as he finds what he's looking for. "I think you know me better than that."

Derek sits on the bed and sets a slim velvet box in front of her. Casey gets nervous and scoots away from him. "What is this Derek?"

"Just open it before you freak out."

She picks up the box and starts turning it around in her hands. "You couldn't at least wrap it?"

He sees through her attempts to avoid opening it. "Casey." This time there's not mocking in his tone.

She finally opens it and pulls out a pendant necklace. Her birthstone is embedded in it. "How much did you spend on this?"

"Well, it wasn't as much as you might think. It's barely anything resembling gold. And I have this feeling the stone might not be real."

"Still," she says.

She has yet to take it out of the box, so Derek takes it from her, removing it himself. "There's an inscription on the other side." He flips it over and shows her.

For once not showing much visible emotion (Derek can't help but think why now?) she reads, "To my favorite person to annoy."

She's definitely unsure what to say at first, which is kind of what he was expecting in the best-case scenarios. (The pendant hasn't hit him the forehead yet, so that's good.)

After her being silent for too long he decides that if anything is going to be said, he's just going to have to say it.

"Casey, I bought this before that night."

"Okay?" (Of course she wasn't going to make this easy for him.)

"Don't you think that means...something?"

"It means that even when you get me a gift you have to remind me what an egotistical jerk you are?"

He holds in a groan. "No." He repositions himself on the bed to face her straight on and continues, "Jesus, Casey." He takes a deep breath. "Do you not get it all?"

"I'm not sure. This isn't exactly new information. Everyone knows you love to torture me. The only real mystery is why you would get that fact inscribed on a necklace."

"Casey, you are my favorite person to annoy. Not Edwin or George or Sally or Emily or any other girl I've ever known. Tell my why you think that is without using the words jerk, asshole or step-brother. "

She smiles a little. "Is bastard allowed?"

He's not playing. "No."

"You think I'm the most annoying person in the world. Again, not news, Derek." Now she's starting to get frustrated and the necklace is fisted in her hands.

"That's not it and you know it." She doesn't say anything. He moves his face closer to hers, trying to force her too look up at him.

"I - I really don't know."

"I don't believe you, but fine." He pauses and pulls away just a little. "I like you. Not like one family member likes another family member, but like two people who make out when they're left alone in a dorm room."

"Derek - "

"It didn't happen, I know. But here's the thing, it did, so we can keep pretending and getting in fights that aren't fun for either of us, or we can actually admit what's obvious to everybody else."

She lets that necklace dangle from her hand. "We aren't that obvious."

"When Joe met you he asked if you were Emily."

"Joe's an idiot."

"And yet even he saw it."

They're quiet for a moment and even though their proximity is definitely driving him crazy (they're on his bed and she is close enough that he can smell her and she smells like sugar cookies and shampoo and he's honestly kind of impressed with himself for not trying anything). He knows she needs time to think, so he lets her.

She pulls back and puts the the necklace in the box, but grabs his forearm before he gets up, thinking she doesn't want it. He sees that she's blinking away tears. "I'm not going to wear it until we get back to school. I'm not ready to tell - " She sort of motions with her heads and head to the house, and he figures that the finishing that sentence with our family is freaking her out a little.

He brushes her knee with his hand. "I'm not sure I am ether."

She smiles. "Good."

Then she kisses him and her hand slides from his forearm to his shoulder and he pulls the rest of her onto the bed.

-------

She wakes up there the next morning, which kind of causes her a great deal of momentary panic, until she a) remembers that they actually talked the night before and b) realizes that they both have clothes on. (She isn't sure she's okay enough with this yet for fully unclothed activities.)

Thankfully, she wakes up early enough to sneak back to her own bedroom. She kisses Derek on the forehead on her way out and kind of feels bad that she isn't going to be there when he wakes up.

-------

When they open presents that morning Nora almost gets upset with Derek for not getting Casey a gift until Casey says, "We kind of exchanged gifts earlier." Although she feels bad about that because the word exchange implies some kind of equal trade, and she's pretty sure that the The Who LP she got him comes nowhere close to what he got her, even if he did seem very happy with it. (He hugged her in front of everyone and she thought Nora and George were going to have heart attacks.) Although, she did let him kind of get to second base-ish, so maybe that counts for something.

Derek spends most of the morning sending Casey inappropriate text-messages which cause her to blush and finally put her phone on silent (apparently he does count second base as a gift).

Casey's already kind of unsure of how they are going to make this work when they go back, especially since Derek can apparently barely manage appropriate decorum in front of their own parents.

But he still keeps smiling at her and somehow that makes her not worry about that quite so much (relativity speaking).

----
She ends up spending a couple of nights of the rest of the break in Derek's room. It's stupid and careless and one of the mornings when he wakes her up he insults her.

She loves it.

When they drive back a week later she lets him drive and pick the music. As soon as their out of sight of the house she scoots closer to him.

They still haven't figured out what it's going to be like when they get back, but they've talked about it. (Most of their talking has consisted of Casey freaking out and Derek telling her they'll figure it out eventually, which kind of infuriates her, because, hello, you have to have a plan.)

Without any kind of prompting on her part, he leans over quickly and kisses her temple. "We're going to figure it out."

She believes him and leaves a little kiss on his neck.

(The trip to school is much more fun than the trip home. Also, it takes a lot longer.)

The end.