On the first day of the second term, Derek walks into his economics class and is delighted to see the back of Casey's head. Predictable as ever, she's seated in the center of the front row, carefully taking out her notebook and pens. His urge to go unnoticed by the professor is trumped by Derek's urge to get under Casey's skin, so he lopes down the aisle and slides into the empty seat to her left. "Hey," he says, leaning over. Casey jumps, and he grins. "Can I borrow a pen?"

"Derek," she hisses, rolling her eyes. "Honestly, how can you come to class so unprepared." She shakes her head at him, but pulls a pen out of her bag and passes it over. When he doesn't move away, she arches a brow at him. "I thought you wouldn't be caught dead sitting in the front row."

He shrugs. "How else am I going to copy your notes?"

"Derek!" So this semester is already going better than the last.

This, more or less, repeats itself a couple hours later when Derek learns they are also sharing Philosophy 101.

The next day, he spots Casey in the dining hall. She's sitting with a pretty blonde and rolls her eyes when he approaches. "What?"

"Can't I have lunch with my favorite person?" Derek asks, innocently. He drops into a seat before she can protest.

She doesn't miss a beat. "Marti isn't here," and she returns to her lunch.

"My mistake. I saw the pouty face and dark hair; how could I not mistake you for Marti?"

Casey makes a face at him, and off they go. It's not until several minutes go by and the blonde laughs at them that Derek remembers he'd intended on flirting with her, getting her name and number. "You're like an old married couple." She laughed harder as Derek choked on his tea, and Casey threw a napkin at her. "What? It's adorable."

"Adorable?" That was a phrase that had never been applied to their bickering before. At least, not as far as Derek knew.

Casey ignores the blonde's nodding head. "Don't you have friends to go sit with."

"I have friends, yes. None that are around, incidentally. Hence my slumming it with you." He grins when he sees the corners of Casey's lips quirk up. As annoyed as she looked right now, Derek knew that she was pleased with every broken rule in the past two days.

Two days later, he shows up at her dorm room. It would have been sooner, but it took all that time just for Derek to find out where she was staying. She blinks when she sees him standing on the other side of the door, and he takes advantage of her surprise to shoulder his way into the room.

It's his turn to be surprised when there's a group of girls huddled on Casey's bed, and a few more scattered around the room.

"Derek," she says, terse. "I thought I told you not to come by here." Their game has always been twisted, so even though she basically told him to break every rule put in place, she's got to stick to the script. It was in Casey's character to create rules just as it was in his nature to break them.

He shrugs. "You know I don't listen to you when you talk." His eyes roam around the room, and they land on a pretty redhead. He winks, and she blushes, smiling back at him.

"I'm kind of busy right now; do you need something?" There's a hint of genuine annoyance in her voice rather than the playful one he's used to. His gaze reverts back to Casey.

"Yeah, I need your notes from philosophy."

"You're joking." He shrugs. Derek doesn't actually need her notes, but he had to have an excuse to see her. It won't hurt to have hers, though, because they're bound to be better than his. "You were there; I'm not giving you my notes. I'll probably never get them back."

His gaze wanders around the room. "That's okay; I can copy them here." He flashes a smile at the redhead again.

Sighing, Casey rummages around in her backpack and shoves a notebook into his chest. He takes the notes, brushing his hand against hers. The sensation he feels as they graze hands is definitely pure disgust. "Get them back to me," she threatens.

"Of course," he agrees. "Ladies," he says to the gathered group who are all watching their exchange with varying degrees of interest.

"Bye," the redhead waves. He winks at her again just before Casey shoves him for the door.

"Honestly, Case, a person might get the idea that you don't want me around," he says as the door slams in his face.

Derek goes to her dorm again the next day. When she opens the door, Casey takes one look at him and promptly shuts it. Grinning a little, Derek leans on the wall next to the door.

Three...

Two...

One...

The door opens again, and Casey stands there with her arms crossed in front of her chest. Anyone else might think she's mad, but there's a slight crinkle to her eye betraying her mirth. "What?"

"Are you busy?"

She blinks, then eyes him suspiciously. "No."

"Good. Let's go." He straightens up, grinning at her.

"Go... where?" In reply, Derek shrugs and tugs on her arm. "Derek! I don't even have shoes."

"Two minutes."

"But-"

"Two minutes and fifty-nine seconds," he lifts his wrist to look at her watch. She starts to say something else, and he continues to count until she slams the door again. With twenty-one seconds remaining, the door opens, and Casey steps out in a huff.

Derek brightens at the sight of her. "Right. Let's go." He takes off.

"Where are we going?" Derek ignores her, continuing on. He can hear Casey treading along behind him.

They end up at a small get together. It's a party, but not like the one Casey would expect him at. Most of the hockey team is there, including their coach and his wife, which is why it's not quite a Party. It's neat, though, because a lot of the members have brought a friend (most of them brought a girlfriend or boyfriend), there's some music playing, and Coach is grilling in the back yard.

"You brought me to a party?" Casey asks, glancing around. It was relatively tame, but she looks wary.

Derek shrugs. "A barbecue, really. Coach wants us to bond outside of practice." Casey looks at him with an expression he's not quite able to read, but she doesn't seem upset, so he takes her around to introduce her to his friends. According to Casey's rules, they're not supposed to spend any time together, she wants nothing to do with his friends or the hockey team, and she doesn't want him getting to know her friends.

He watches as she chats animatedly with the goalie, Mack, and his girlfriend, Angela. Despite another rule broken, Casey doesn't look too upset.

Things continue in this way, and soon enough, they're home for the summer break. Summer, too, has its own set of rules. Some of the rules come from their parents as they try adjusting to the change that comes with coming home after two semesters of college. Derek and Casey have found a bit of independence living away from home, and to be back under their parent's roof as if they were in high school again is strange. They wind up with a bit of compromise. There's a time that his dad and Nora would like for them to be home; any later than that, then please be quiet and try and give their parents an update on when they'll be home when possible.

Casey gives him rules, too. Mostly about how they're not going to spend time together over the summer, how he's not to prank her or touch any of her things, and how she will not be helping him get registered in time to get the classes he wants.

Naturally, Derek breaks all of those rules. The rules his dad lays out are followed, more or less, though he does toe the line.

On the way back to Queen's for their second year, Casey once again starts in on the rules for the semester. Exasperated, Derek clutches the steering wheel. "Casey, I already know the rules. Can we not, please?" It's a long drive, and though he knows that most of her rules are for show, he'd prefer not to go through the whole thing again.

"But these rules are different, Derek," Casey insists. He groans a little, tuning her out as she starts in on the things Derek isn't allowed to do this year.

It's about a minute later when he catches, "... or kissing me. Not allowed."

"Wait. What?"

Casey huffs, glancing at him out of the corner of her eye. "Were you even listening."

"No."

"Honestly, Case, I don't know why you're surprised." He flexes his fingers on the steering wheel, mind going. Had he imagined that?

She shrugs. "I don't know why I bother, but you missed the most important one."

"What's that?" He asks, pulling into a parking space in front of her dorm building. His mouth feels dry.

"I said you're not allowed to touch me for anything; no teasing hair pull, slinging your arm around my shoulders, nudging me with your shoulder, or kissing me."

"Kissing you?" If Derek were to be a hundred percent honest, he's imagined kissing Casey before. Usually, the thought rose unbidden during the height of one of their more intense verbal spar sessions. He liked to pretend it didn't happen, though, that the thought never occurred.

Of course, now that Casey had spoken the idea out into the world, it was all Derek could think about.

"It's just an example, Der," Casey says. She reaches for the door handle, and Derek tugs on her elbow. She sits back, staring at him. He opens his mouth, then closes it.

Trying again, Derek licks his lips and opens his mouth to speak. Words fail him. His mouth closes. The smile on Casey's face shifts to something a little more forced.

He thinks about last year when she listed all the rules with the expectation that setting them would result in him breaking them. This can't possibly be the same thing. It was a test of sorts; it had to be.

The corners of Casey's eyes tighten. "It was just an example in a very long list," she says. Her voice sounds strange, but Derek recognizes the inflection. She's trying not to cry.

He leans in, pressing his lips to hers in a warm kiss. It lasts for only a second. Pulling back just far enough that his eyes can focus on hers, Derek's mind whirls. Had he really just done that. "School hasn't even started," Casey says, sounding breathless, "and you've already broken that rule."

At that moment, Derek decides he wants to hear Casey's voice like that toward him far more often. He leans in and kisses her again, this time a little more urgent. It's still a bit hesitant until he feels Casey's lips part, and she's kissing him back. Then his hands are tangled in her hair, and she's just made a small noise in the back of her throat.

Derek's never enjoyed breaking a rule more than that one. "You wanted me to," he argues when they break apart, both trying to catch their breath.

Casey grins. "If there's any way to get Derek Venturi to do something, it's to tell him he can't."

"That one was implied long before this trip."

She shrugs, kissing him once more. Her voice was soft as she said, "Yeah, but I figure if I made it a rule, you might figure out that I was okay with it happening."

"It took me a minute," he admits in a low voice.

"I noticed." She exhales. "I thought you didn't want to kiss me."

Derek barks out a laugh. "I've wanted to kiss you since we were fifteen." He leans in for another kiss, but they jump apart at the sound of a honk from behind them. Right. Moving in. There was time for more kissing. Later.

Laughing, Casey climbs from the car, and he moves to help her get her stuff. "There will be rules, you know," she says mildly.

"Of course," he offers her a long-suffering sigh.

"The kind that you actually need to follow," she says stern.

This he had already expected. He figured it would mostly be stuff like making sure he wasn't dating around and such, but that was fine. He didn't want anyone else. "Casey, haven't you figured it out already, I'll follow rules for you."

It's not quite the sweetest line in the book, but it's sincere and coming from Derek, it means a lot. Which explains the look on Casey's face as she pauses on their trek to her dorm. "Alright," she says.

"Alright," he agrees with a smile.