A/N: Just to warn you now, Chapter 2 will be almost exclusively smut, and will only be posted on my LJ. I'll link to it from here. For anyone in need of graphic smut to tide them over while I finish Chapter 2, there are a couple of dirty new one-shots up already - basically, if I've linked to it on my author page but not posted it here, it's PWP.

Disclaimer: Portal is Valve's, not mine.

.

A Professional Relationship

Sometimes science is hard work.

Cave Johnson sighed forlornly. He had a mountain of papers to sign, a list as long as his forearm of calls to return tomorrow, and he'd been staring at this budget so long his vision was starting to blur. Late nights in the office were his norm, but this one was getting too late even for him—he desperately needed to unwind. He rubbed his eyes with the heels of his palms and wished for a bottle of Jack Daniel's.

"Would you like a drink, sir?"

He removed his hands from his eyes to see his pretty assistant, a glass in her hand. Suddenly things didn't look so bad.

"Caroline, you're a gem." He accepted gratefully. One of Caroline's many talents was the ability to mix a perfect Jack and Coke. With a single sip he felt the tension in his muscles start to ease—her hands massaging his shoulders, unasked for but very welcome, did the rest of the job. His sigh now was one of contentment. "How do you always know just what I need?"

The compliment made her smile. "That's what I'm here for, sir."

Her expert fingers on the knots in his back felt exquisite. He shifted to allow her better access and relaxed into her touch.

She, meanwhile, was peering curiously over his shoulder at the papers on his desk. "What're you working on?"

"Budget crap. Don't know why the bean counters won't take care of it. All I'm asking for is enough to build a giant chicken coop for the giant chickens they're breeding in the lab. They've got 'em about dog-sized now, but if this thing works they'll be bigger than horses. We could end world hunger! Or at least that's what I keep telling Accounting, but they don't seem to buy it."

Caroline moved around him to get a better look at the figures. "How much do we need?"

"Enough for the enclosure, and the light and water systems, and chickenfeed for around forty super-birds. A couple of million oughta do it. I just don't know where that'll come from."

"What about the shower curtains? They're selling better than ever."

"Thought of that. Our buyers are taking as much as they can handle already."

A spark of inspiration lit suddenly in Caroline's eyes. She whirled to face him, wearing a confidential grin. "So why don't we find some new buyers?"

"Like who?" She had his full attention now—he had no idea what she was getting at, but her moments of brilliance like this were captivating.

"What about the military?"

Cave blinked. "What?"

"They need shower curtains as much as anyone, and ours are the best. Waterproof, fireproof, bulletproof, airtight—they're military-grade already." Her words were slow and deliberate and dripping with excitement. "Call the president. Set up a meeting. Make Aperture Science the official shower curtain supplier of the US Armed Forces."

"That's…" Cave's face broke into a colossal grin. "Caroline, that's brilliant!" He bounded up from his chair and swept her off her feet.

Caroline laughed in surprise. "Mr. Johnson—!"

"You're a genius! You're a goddamn genius!" He whirled her in a circle. "Accounting can kiss my ass! We'll make a fortune!" At last he set her down, but his strong arms stayed wrapped around her in a tight hug. He murmured into her hair, "I don't know how I ever got by without you."

Pressed to his chest, her nose was filled with the warm masculine scent of him. She flushed and felt her heart skip. "Just doing my job, sir." She heard the breathlessness in her own voice and her flush deepened.

He heard it too, thought his hug was crushing her, and let her go. A smile teased his mouth when he noticed her blushing—she was so damn cute when she tried to be modest. "I think that's enough work for tonight. Let's take a break, huh?" He grabbed his drink from the desk and found a seat on the sofa across the room, putting his feet up on the coffee table as if he hadn't a care in the world.

"I still have things to finish, sir." She started to go.

He held out a hand to stop her. "Hey, hey, it can wait. C'mon, sit with me." He patted the yellow upholstered cushion beside him invitingly.

She paused, indecisive for a moment, then relented with a shy smile and sat. He threw an arm around her shoulders—without thinking, she relaxed into his side. The picture they unconsciously created was like nothing so much as teenage dates at a drive-in movie.

Cave took a sip of his drink and sighed in satisfaction. Not a bad end to the day—a million-dollar idea for the morning, a place to rest his feet, a Jack and Coke in one hand, and a pretty girl at the other. He glanced down at her. Her head lay pillowed on his shoulder like it was the most natural thing in the world. Cute as a those big brown eyes, and that soft pink mouth, and that gorgeous body snuggled under his arm, a sexy little kitten—

Stop it.

And there it was—that weird mental roadblock he hit whenever he thought of her sexually. And he did—often. Who wouldn't? She was young, and pretty, and around him all the time, and he just couldn't make himself do anything about it. Normally he was a Casanova—a little sweet-talk, a suggestive smile, and he was alone in the break room with the woman of his choice. So why couldn't he pull his usual tricks on her?

He was a go-getter. A man of action. A stud. He was a man who took what he wanted—and he'd never wanted anyone so badly in his life.

So why did those sweet chocolate eyes stop him in his tracks?

Those eyes were on him now, he noticed abruptly, peeking upward from under long dark lashes. He felt suddenly torn. One half of him wanted to kiss her right on her pretty mouth; the other half warned, Don't you dare. Let go of her before you do something stupid. Cave Johnson was not a man accustomed to internal conflict. He did neither—he simply stared transfixed until she shyly averted her own gaze.

He cleared his throat. "It does me good to have a young thing like you around, Caroline. Makes me feel young again myself." Great. Now I sound like her grandpa. Not like it makes any difference, she's too young for me anyway—

But the way she looked at him now made him almost think she read his mind. "I'm not all that young, sir."

"Come on," he scoffed. "What are you, nineteen?"

"I was nineteen when you hired me, Mr. Johnson. It's been five years."

He blinked. "Has it really?" That put a different spin on things. Not much of one—she was still too young for him—but… like she said, not all that young. Her eyes on him showed no trace of bashfulness now. "And I've never seen you clock out before me. Why do you spend all your nights cooped up in this place?"

"Because I like to." Her tone said that it should be obvious. "I like how it's quiet and peaceful, I like getting extra work done, I like when it's just you and me—" She heard herself and bit back her words too late. A blush rose to her cheeks, she looked quickly away, and her shyness settled like a veil over her face. "I like it," she finished quietly.

Damn that shyness. He tried to draw her out again. "Shouldn't you be—I dunno, out having fun, meeting men, whatever kids do these days?"

That did it. Her eyes snapped sharply back to him. "I don't know what other people do, sir," she said haughtily, "but I do science."

He laughed. "Caroline, you are my kinda girl."

"I try." Her smile was less bashful and more proud. "In fact—" She lit up with another idea. "I know just what you need."

"What's that?" But she had already slipped out from under his arm and seated herself daintily on the coffee table across from him.

She took hold of one foot and eased off his shoe. "I bet your feet are aching after such a long day, aren't they?"

"Aw, Car—" His protest turned into a groan of pleasure as her thumbs dug into the arch of his foot. "You're just good at everything, aren't you?"

Her shy, proud smile grew. "I try."

With another groan he melted blissfully into the couch, surrendering to her skilled hands. "You're gorgeous, you're smart, you make a great Jack and Coke, and your idea of a good time is staying late in the office to give me a foot rub. Why the hell haven't I married you yet?" Blushing slightly, she kept her attention fixed on his feet—she didn't trust herself to reply. Thankfully the question was rhetorical. He flexed his foot and sighed. "I must've done something spectacular to deserve you."

That she did know how to answer. Eyes still demurely downcast, her smile returned. "You're Cave Johnson, sir. Everything you do is spectacular."

"Damn straight!" he laughed, and finished his Jack and Coke in one long gulp. She paused the foot massage long enough to take his empty glass and set it on the table beside her. "You really don't have anyone you'd rather spend an evening with?"

"No, sir," she said firmly. "Aperture comes first."

She's a regular little propaganda film, he thought, a bit awed. It was heartwarming and unsettling and—dammit—cute. She really was something special. He persisted out of curiosity. "C'mon, no friends, no sweethearts? A girl as pretty as you's gotta have a man in her life."

"I have—" She caught herself this time. "I have science, sir."

"You don't have a beau or anything?"

"I've already given my heart away." Her tone held a touch of wistfulness. Her eyes stayed on his feet.

"Lemme guess—to science?"

"Yes sir."

"It was a tragedy for men everywhere the day you came to work here, huh?" He chuckled and folded his hands behind his head. "Hell, if I were ten years younger you'd never get rid of me."

Focusing on her task lessened the comment's unintended sting. She switched to the other foot. As she removed his remaining shoe, she said in a forced-casual tone, "Some women like older men."

"Aw, don't tease me, kid."

"It's true." She rubbed slow, contemplative circles into his foot as she talked. "Young men are immature and boring. Some women prefer a man who's more… worldly. Intelligent. Worthy of respect. A man with willpower. A man who's so confident and strong that being with him makes her feel confident and strong too." She felt herself sliding into reverie and gave herself a little shake. Returning to her casual tone, she finished, "A man like that could have any woman he wanted."

He scoffed, "Never met one."

"I have."

"Oho! She's smitten after all!" Curiosity got Cave's attention—and a sudden flash of jealousy flared in his gut. He swung his feet off the table and leaned forward. "Who is he?"

She didn't have feet to focus on now. Before she could stop herself, her eyes met his.

In that heartbeat, their dark depths swallowed him whole. He saw her—timid, uncertain, but aching for something he had to give. He wanted so badly to touch her, to hold her and kiss her and make her his, but that damned insecurity kept him at bay. There was something delicate in those eyes—and that scared him. He broke delicate things. He didn't want to break her.

She dropped her gaze to the ground, cheeks burning, and whispered, "I was talking about you, sir."

But he wasn't going to let that shyness have her again. "Hey, kid—" He reached out to stroke her cheek. She looked up at him again, eyes wide, soft little mouth barely open in surprise, and with one last thought—You're Cave Johnson, dammit—he screwed up his courage. The words came out in a husky whisper: "Can you guess what I need now?"