A/N: I feel a little explanation is warranted here, just in case I have any returning readers. Anyone who has read my stuff before knows that I have always written in the Harry Potter fandom, and not posted a story in nearly 2 years. I had to go live like a grown-up, you see, and sort of fell away from fanfiction. However, I'm home for Christmas for a week and was catching up on some shows I haven't had time to watch lately, and realized how very much I love the Big Bang Theory. With time on my hands and no adult supervision, that love translated itself into fanfiction has it has not done for me in a long time. I saw no reason not to post it. I hope no Harry Potter fans are disappointed, and I hope any fans of TBBT enjoy the story!

Title: The Osculation Definition

Pairing: Sheldon/Penny

Rating: T, for adult language and adult behavior

Spoilers: 3x11 especially, and occasional tiny references to seasons 1&2

Disclaimer: Not mine. Wouldn't have time for them even if they were, so it's probably better this way. Although I'd make time for Jim Parsons. Lots of time.

Summary: Sheldon gets kissed. Things evolve from there.

Sheldon Cooper liked math. He did not like people. Subsequently, although he liked osculation as defined in the realm of mathematics, when it referred to arcs touching at a point of common tangency, he assumed he would not like osculation as defined in the realm of human interaction. Kissing had always bewildered and faintly nauseated him. He hypothesized with confidence that he would dislike the entire unsanitary practice, and did so with confidence despite the lack of any experimental evidence to support it.

When Dr. Beverly Hofstadter kissed him, his hypothesis seemed proven correct. It was awkward, vaguely unpleasant. It tasted of agave-based ethanol and waxy cosmetics. He had no desire to repeat the experience.

He was rather intrigued with the way Penny's irises had flashed briefly emerald in the dim light while she looked on at the travesty of Sheldon Cooper's first kiss. He wondered why they had done that, and what variables would have to be in place for them to do it again.

On New Year's Eve, Sheldon was forced against his will to attend an incredibly loud and disorderly party at Penny's apartment. He stood near the kitchen with Koothrappali, taking some small measure of solace in the fact that Raj's expression of abject terror and his proximity to Sheldon generally dissuaded chatty guests from approaching them.

Leonard approached Sheldon's corner in a rather stumbling fashion that indicated impairment of spatial comprehension and gross motor skills.

"Having fun, Sheldon?"

"No, Leonard, I am not having fun. I am at a social function populated entirely by inebriated degenerates. My preferred companions are rendered intolerable or absent company by their inability to resist their primitive biological imperatives. It is Wednesday night and Wednesday night is Halo night, but I am not playing Halo. I could hardly be having less fun, could I?"

Koothrappali gave an inaudible gulp and Leonard blinked myopically, clearly too impaired by his alcohol consumption to comprehend Sheldon's diatribe. Sheldon heaved a long suffering sigh and tsk-ed at a befuddled Leonard.

"I'm leaving," he said shortly. Leonard quickly leapt into action and caught himself just before he committed the strike-worthy offense of grabbing Sheldon's elbow before he could escape.

"Don't leave," Leonard whined. "At least stay until midnight. Please. It'll hurt Penny's feelings if you go."

Sheldon glanced across the room, where Penny's dress and hair and lips and champagne glass all sparkled rather gaudily as she carried on an animated conversation. "I fail to see how my presence will affect her in the least."

"C'mon, Sheldon. Please stay. She wants you to."

Sheldon stayed. It was not because Penny wanted him to do so. He made certain to express his displeasure to anyone foolish enough to make eye contact with him.

When midnight struck, there was much bacchanalian celebration and considerable destruction of brain cells and private property. Sheldon's height made it possible for him see Penny and Leonard on the other side of the chaos as Penny threw her arms around Leonard's neck and kissed him soundly, disrupting Leonard's tenuous ability to remain balanced and upright. They stumbled into a wall and Leonard promptly lost his footing and fell to the ground. When Penny laughed, the spangles of her dress flashed in her eyes and they turned the peculiar shade of golden-green that Sheldon had only ever seen before during early mornings in Germany, when sunlight hit the fir trees, when he was fifteen and very alone.

Sheldon did not want to kiss or be kissed at midnight. He also did not want to be at that party a moment longer than absolutely necessary, so he quickly escaped while the revelry was still at its climax and he was unlikely to be missed. He went back to his cool, quiet apartment and did not feel lonely. After his evening ablutions, he considered his Wednesday pajamas, which were green, and had a moment of irrationality in which he nearly threw order and method out the window and wore his back-up Wednesday pajamas (an innocuous shade of burgundy) instead. He quickly regained a hold on himself and dressed in his Wednesday sleeping attire, which were a normal, unremarkable sort of green, and did not in any way resemble fir trees at sunrise.

In late January, Penny landed a small role with a local theater company, and she spent almost every evening either at rehearsal or picking up extra shifts at the Cheesecake Factory to help make up for the ones she would miss when the play went into production. Sheldon found his routine unpleasantly disrupted by her absence, not to mention Leonard's new hobby of moping around their apartment like someone had stolen a Nobel from him.

"Really, Leonard, I feel at least a small modicum of self-respect is in order. It's not as if Penny has ended your farcical carnal relationship. You're acting like my sister after Bobby O'Hallahan dumped her at senior prom."

"I never see her anymore!" Leonard complained from his chair, where he was sitting curled up in his bathrobe eating a soy-based Chunky Monkey knockoff directly from the carton. Sheldon made a mental note to immediately discard said container, assuming Leonard didn't manage to consume the entire quart in one sitting. "It was one thing to sit at home alone every night before I knew what it was like to have a girlfriend. Now it's just pathetic."

Sheldon stared at his roommate. He felt his left eye begin to twitch.

The front door opened and Walowitz and Koothrappali walked in carrying several bags of take away and arguing strenuously over the relative merits and weakness of Uncharted 2 versus the new Call of Duty. They began distributing styrofoam boxes of burgers and fries and Howard carefully pried the melted pseudo-ice cream out of Leonard's resisting fingers.

"You'd better lay off the Chunky Monkey there, compadre. It's going to go straight to your hips, and who will want you then?"

"Yeah, dude," Raj chimed in as he settled down at his end of the couch. "Penny's going to find a younger, thinner, more successful physicist, and you're going to end up growing old with Sheldon and seven hypoallergenic cats."

Leonard scowled at them and pulled his robe closed around his throat. "I'll have you know that even on my worst day, I'm still dating a beautiful blonde actress, and thus I'm still in a distant first place as far as the occupants of this room are concerned." He sullenly pushed a few fries around his styrofoam container. "I just miss her, that's all. I need something to distract me."

"Leonard, your mother kissed me," Sheldon supplied helpfully from his spot, just before taking a large bite of his burger. When he finally looked up from his food, Penny was not still not there. If she had been, he did not think her eyes would have been the same sickly, grayish green that Leonard's face was turning, but one never knew about Penny's eyes.

Sheldon was sick. He was sick and miserable and alone, because his supposed "friends" were all "at work" fulfilling their "obligations." Sheldon failed to see how tending to his needs during his convalescence did not qualify as an obligation.

He was on his spot on the couch, wrapped in a cocoon of blankets, sitting in complete silence as he tried to detect the rattle of pneumonia in his breathing. Between breaths, he occupied himself by frowning at the small pile of Penny's things he had collected on the coffee table. He kept hoping that if the pile grew large enough, she would eventually comprehend that no matter how many nights she slept in Leonard's bed instead of her own, he did not condone her leaving toothbrushes and copies of Cosmo and a single, dirty, tangerine-bright sock in their apartment. So far, this hope had gone unrealized.

He idly contemplated the merits and disadvantages of shuffling to the kitchen for a cup of tea. He was tallying a mental list of pros and cons when the door swung open and Penny burst into the room with her arms full, humming tunelessly.

"Hello, sicky!" she chirped, toppling her burdens rather carelessly onto one of the chairs. For an April in Southern California, the temperature was unseasonably cool, but Penny's long bare legs always made their appearance around St. Patrick's Day and, like the postal service, were not to be dissuaded by a little inclement weather. Today, her shorts were a pale, sunny yellow, and Sheldon instantly disliked them.

"What do you want, Penny? I am attempting to meet my approaching death with dignity and aplomb, and your presence will not assist me in that endeavor."

"I want to make you feel better, Shelley," she teased ruthlessly. "But if you keep on being mean to me, I'll just have to take this very special fell-all-better cake that I baked from your Meemaw's recipe and go back to my apartment and eat it all by myself."

Sheldon eyed the proffered dessert with considerable suspicion. "I distrust unfamiliar baked goods, Penny, and I am very ill," he warned, watching the plate she balanced with a waitress's skill out of the corner of his eye.

Penny waggled her eyebrows at him, waving the cake in his direction by swaying the heavy platter precariously in front of his face. "It's an awfully good feel-all-better cake, Sheldon. It even has blue and white sprinkles on it, just the way you like it. I had to go four different places to find just blue and just white sprinkles, because I knew you wouldn't want me to pick them out of the multicolored sprinkles, but it was worth it." This last was said with a solemnity that Sheldon suspected was a form of sarcastic mockery, but he was too sick and too intrigued by the cake to call her on it.

"I suppose I could eat a piece," he conceded in his most magnanimous inflections. "A small piece." Penny grinned at him and handed him a slice, munching happily on her own serving. Sheldon ate in silence, and surprised himself by not informing her that he was relatively sure she had completely miscalculated the vanilla extract vs. cinnamon ratio. After cake, Penny sat with him throughout the afternoon, watching reruns of The Twilight Zone. She even made him tea, and although the quality was vastly inferior, he found it comforting.

Just before Leonard was due to arrive home from work, Penny cajoled him into taking a nap. As she helped him to bed, she offered to sing Soft Kitty to him, and he heard himself declining her offer.

"What does your mother do, when you are sick?" Sheldon asked her, and for perhaps the first time in his life, he had not been aware of the question before he asked it.

Penny stared at him strangely, and in the half-dark of sunset through his curtains, her eyes were the same coppery green as the patina on his Meemaw's watering can. She leaned forward and Sheldon had the most absurd notion that she was going to press her half-parted lips against his own, and was seized with blind panic. Instead, she changed her trajectory slightly to the left. He felt her long yellow eyelashes brush against his cheek in a purposeful manner, like quick caresses, and felt a flush along his cheekbones that he attributed to fever.

She pulled back and studied him seriously. Her face was unreadable, as most faces were to him, but he thought he knew her well enough to understand that the furrow between her brows denoted inner turmoil.

"What does your mother call that?" he asked.

"Butterfly kisses," she answered after a while, and she got up to leave. When she turned back to him at the doorway, her face was in shadow and the furrow was deeper. "Feel better, Shelley." The door clicked shut behind her.

He did not feel better. In fact, he felt considerably worse. His heart rate had accelerated rather alarmingly, and he had the strangest fluttering sensation in the general vicinity of his stomach. He also thought he could still feel Penny's eyelashes sweeping against the skin above his zygomatic bone. He was so busy attempting to reconcile cardiovascular distress, gastrointestinal symptoms, and tactile hallucinations with his current self-diagnoses that he forgot to listen for signs of pneumonia, and quickly fell asleep.

Penny and Leonard's relationship did not end as quickly as Sheldon had predicted, but it did end, so he was still right. They began sniping at one another one rainy Tuesday afternoon in late August, and this by-no-means unusual occurrence took an unusual turn when Penny countered Leonard's "Fine, I'll just take the movies back on my way to work tomorrow" with "I think we should break up."

Howard and Raj looked at one another, looked at Penny, looked at Leonard, and walked out the door without a backward glance. Sheldon thought about leaving as well, but didn't have anywhere to go or anyone to drive him, so he simply retreated to his room. He had almost made it down the hallway before Leonard started sputtering angrily and Penny began to cry.

The fight was long, and bitter. Sheldon sat on the floor and read the same vintage issue of X-Men over and over and over until the shouting stopped. He heard a few words in low voices, the stomp of retreating feet, and the crash of a slamming door.

When he determined the coast to be clear, he carefully made his way out into the rest of the apartment. Upon first glance he saw no one occupying the communal areas, and wondered for a moment if Leonard had somehow managed to slip into his bedroom without Sheldon having noticed. Then he saw Penny, sitting on the floor as if her legs had simply given out beneath her where she stood, partially blocked from his line of vision by a chair. She looked very small.

When she raised her eyes to him, they looked like enormous pools of green water, like the Pacific after a storm. She quickly closed them, and tears spilled out and trailed down already-damp cheeks. Sheldon felt inexplicably helpless.

"Leonard left?" he asked.

"I left him first," she whispered, dropping her head onto her up drawn legs. After a moment of indecision, Sheldon folded himself down to sit beside her, abnormally aware of his elbows and knees. He contemplated the dismally few platitudes that peppered his vocabulary and found none of them sufficient to the task of comforting a weeping young woman who was curled in upon herself on his living room floor.

Several minutes passed in which Penny cried quietly and Sheldon devised and discarded several possible techniques to bring an end to her distress. Finally, he did what he usually did in social situations that defied his understanding: he began to talk about things that did not.

"Did you know, divorce has been generally uncommon until modern times with three notable exceptions? One is ancient Japan, where nearly one in eight marriages ended in legal dissolution. The second is Islamic culture, which has long accepted divorce and refers to it as talaq." By now, Penny had raised her head to look at him with a mixture of disbelief and bemusement in her red-rimmed eyes. Sheldon hurried on to what he believed was his strongest and most relevant point. "The final exception is ancient Rome. Roman civil law embraced the maxim 'matrimonia debent esse libera.'"

Penny watched him seriously, which was unlike her, but she had stopped crying, so that was certainly something. "It means," he went on, "'marriages ought to be free.' It means either person in a relationship should be able to dissolve it if for some reason it proves to be unsatisfactory."

Penny blinked at him. He was not sure she understood. Then she sighed deeply and shifted slightly in his direction until her tightly curled form leaned against his arm. Her hair, in utter disarray, tickled his ear, his chin, the line of his jaw. "Keep talking," she said in a small voice.

So Sheldon talked. He spoke of the marriage rituals of African tribes and the history of the Anglican Church's split from the Vatican on the issue of divorce. He related the Biblical tale of Solomon, who was said to have had 700 wives and 300 concubines, and told her about his great-grandfather, who had been married to one woman for sixty years and loved her every day of it. Sometimes, as he spoke, he turned his face toward her. He did not kiss her, because he did not believe in kissing, but as his lips formed words they brushed against her fine, downy hair, and if it wasn't kissing, it was as close as Sheldon had ever come on purpose.

By the autumn, there was a new pile of someone else's belongings on Sheldon's coffee table. Her name was Mary, she was a doctoral candidate in neuropsychology at the university, and Leonard looked at her like Sheldon had once seen him look at a limited edition Han Solo action figure in its original packaging that had been on display at ComiCon. Among Mary's more amenable qualities was the fact that she never let the pile on the coffee table get too big and that she could be trusted not to sit in Sheldon's spot even when he was not there to monitor her.

Sheldon liked Mary. He very much liked that her relationship with Leonard had seemed to restore equilibrium to Sheldon's social circle, and Penny was now able to come over for Thai food and Halo and occasional quests on Age of Conan without everyone becoming unnaturally tense and Sheldon constantly being aware that social rules were in play of which he had no grasp whatsoever. Sheldon had found it distinctly unpleasant to miss someone who lived on a few feet away.

It was this disconcerting thought that was occupying Sheldon's mind as he walked into the laundry room at precisely 8:15 on the second Saturday of November. He looked up to find Penny perched on one of the dryers, frowning at a bottle of laundry detergent as she attempted to read the instructions. This was not unusual. He did not know why Penny had changed her laundry schedule, but for six of the past seven Saturdays, she had been his companion in the laundry room at 8:15 every Saturday. He thought he should probably be perturbed to have his routine thus disrupted, but he found her company not unpleasant, so he had allowed the behavioral anomaly to pass unremarked.

"This print is too damn small," she pouted without looking up. "What kind of sadist prints these things?" Sheldon went to his preferred machine and began loading his carefully separated whites into it.

"Penny, as I have told you repeatedly, I suspect you need corrective lenses. You are hyperopic. The print is not too small, your optical lens is simply malformed and does not correctly focus light onto your retina." Penny scowled at him and hopped down from the dryer. She walked over to her open machine and simply dumped the detergent in with flagrant disregard for its intended use.

"You don't fool me with your fancy words, Sheldon Cooper. You just told me I need glasses, and I do not need glasses."

"I don't see how you can possibly make that assumption. Unless you have been very craftily attending night classes without our knowledge, you do not have a degree optometry, and thus are not qualified for that kind of definitive self-diagnosis." His colors were now going into another machine, and he carefully measured out the correct quantities of detergent and fabric softener to optimize the wash cycle. Penny hopped up on the machine next to his and swung her bare feet back and forth, bouncing her heels off the washer with hollow clangs. He noticed that her toes were painted with a sparkling lavender polish.

"So what you're telling me is that either, number one, when you're not being a big-shot physics guy you moonlight as an eye doctor, or, number two, you're a big, fat, hypocrite?" She smiled brightly at him, mischief evident in the twist of the left corner of her lips and the defiant tilt of her tiny chin.

"Now, Penny, who taught you that big word?" Sheldon asked as he brought his gaze back to his laundry.

"Sheldon!" Penny squeaked. "Did you just make a joke?" Sheldon resolutely did not look up from the quarters that he was slowly counting out and loading into the machine.

"You did!" she practically crowed. "A real live joke!" She leapt down and went scrambling through the accumulated forgotten and discarded belongings that cluttered the shelves along one wall.

"What are you doing?" he asked her. She returned to him triumphantly with a broken pencil in one hand and an old receipt in the other. She was scribbling something on the back of it. She finally presented the scrap of paper to him with a flourish. The date, time and place were inscribed upon it, along with her signature.

"I'm recording this for posterity. Sheldon Cooper's first successful attempt at humor. I thought we could frame it. Put it on your wall next to your all your science plaques and stuff." Sheldon felt a bright rush of anger at her flippancy, her joking tone as she referred to his most precious possessions. Why her opinion mattered completely perplexed him, but hearing her belittle his degrees and awards stung painfully, and he felt the irrational urge to lash out in response.

"Those 'plaques and stuff,'" he ground out between his teeth, "are the awards and acknowledgements that comprise my greatest accomplishments as a scientist and an intellectual. They are not a joke. They are who I am."

Penny's gaze went suddenly dark and solemn. She reached up quickly, before he could think to pull away, and put her hand against his chest.

"Those things aren't you, sweetie. This is you." She waved the receipt she held in one hand. "This is you." She tapped a small finger against his breatbone. "And I only joke about your physics stuff because it goes so far over my head, and I hate feeling stupid around you." She sounded so suddenly vulnerable and unsure that he opened his mouth to respond, but she quickly added, " . . . and the rest of the guys, of course."

"Of course," he echoed faintly. He felt strangely unsteady, as though her hand against his ribs was the only thing holding him upright.

"You're more than those stupid plaques, Sheldon," she said earnestly, quietly. "I hate that you think that."

"I –" He found himself unable to complete his sentence. He was acutely aware of every ridge of her slim fingers over his Flash insignia, the way her breathing had grown erratic and shallow, the startling dart of her pink tongue as she licked her lips. He suddenly felt very frightened of Penny.

"Have you ever kissed a girl, Sheldon?" Penny asked, and her voice did not sound like her but it still made him shiver.

"I believe you bore witness to Leonard's mother's attempt at osculation with me. I have had no other experiences in the matter." He couldn't seem to stop looking at her lips, wondering if that small quick tongue would make a reappearance, but he didn't need to see her eyes narrow in confusion to know she needed clarification. "Osculation. It means kissing."

"Now, Sheldon," Penny breathed, "who taught you that big word?"

Her lips were very soft, and she did not taste like tequila or lipstick, but she did taste of summer. Sheldon found he wanted to keep his eyes open, wanted to see her, but they closed against his will. It was over quickly. He found that this time, he wanted to repeat the experience.

He moved forward again, hoping she would react accordingly. Penny, ever to be depended upon to plunge forward and think later, rose to the occasion. He found he liked this kissing business better when he could sink his fingers into her long, disheveled hair, when she lifted up on her toes and pressed her slender frame against him, when that clever, fascinating tongue slipped along the seam of his lips. He experimented with angles and pressure. Maneuvers that received a positive response were repeated. He discovered that kissing and breathing simultaneously required a kind of coordination of which he was not yet possessed. Eventually, the need for oxygen overrode his other biological urges and he was forced to pull away.

Her eyes were that perfectly clear, utterly luminous emerald color again. It seemed the only thing he had to do to make that elusive shade appear was kiss her. He was not particularly bothered by the prospect.

"Sheldon, you down here? Mary and I brought dinner . . ." Leonard rounded the corner at just that moment and stopped short when he saw Penny, who was now standing a respectable distance away from Sheldon. Sheldon felt the space between them pull like the allure of opposing magnets. "Oh, hey, Penny," Leonard said brightly, with a genuine, guileless smile. "I forgot you do your laundry on Saturdays, too. There's plenty extra. Want to have dinner with us?"

Penny glanced at Sheldon. A small muscle jumped in her jaw as she set it determinedly. He wanted to run his lips over that muscle, feel it stretch and leap beneath his fingers. The look on her face seemed to say, "this isn't over, buddy." The glance was over in an instant, she turned to Leonard with a grin that was utterly casual.

"I would love dinner, Leonard. I'm starving!" Penny announced cheerfully, and nearly skipped past him out the door. Leonard turned to Sheldon with a slightly perplexed expression.

"What's she so happy about?" he asked.

Deciding discretion was the better part of valor, feeling a bit like Clark Kent slipping on his glasses, Sheldon replied, "I haven't the faintest idea, Leonard. What kind of food did you bring? It's Saturday. You know I prefer not to eat Asian cuisines on Saturdays." The conversation continued in this vein all the way upstairs, and Sheldon very cleverly did not say "oh, and I just kissed Penny in the laundry room" no matter how much he wanted to.

Penny was a very good kisser. She was also a very good teacher. Sheldon thought it was a terrible shame that she wasn't more intellectually gifted, because she would have made an excellent educator. He consoled himself with the knowledge that most students' minds were too prosaic or apathetic to have benefitted from what was so clearly a gift.

He never knew when an impromptu teaching session would occur. Once he was walking downstairs to collect the mail, met Penny as she was coming up, and found himself pinned against the wall of stairwell halfway between the second and third floors while she made an admirable attempt to climb up his body like one of the ropes from high school gym class. In another instance, he woke up to begin his early morning ablutions and discovered Penny perched on his bathroom sink with a smile on her face and his spare key twirling around one finger.

Like all good teachers, Penny's curriculum made Sheldon see familiar things in a new light. After one rainy weekend in January while Leonard and Mary were out of town, Sheldon was never able to even look at his spot on the couch again without blushing most alarmingly. Following a brief tour of his Caltech offices and labs, Penny had forever changed his appreciation for the exact height of his desk. And he never again scoffed at Leonard, Howard, and Raj's inability to resist their own libidinous urges. Once his own were awakened, even he, who was so clearly vastly superior to his friends and colleagues, could not always draw his eyes away from Penny's mouth when she spoke, or stop thinking of her when he lay in bed at night, aching.

Sheldon's education continued in secret for nearly two months. When they were alone, Penny was fire and ice in his arms, terrifying, wonderful. However, when in the presence of anyone else, Penny was just Penny. She did not kiss him, or crowd his space, or run her slim hands over skin that had barely ever known sunlight, let alone the hands of a someone other than himself. She did not even touch him. For a long time, he found this comforting. It was good to know that this was the same Penny he had always known, who did not understand physics, whose apartment was in a constant state of chaos, who occasionally drank too much, who was really not a very good actress, all things considered.

Then, while watching Dr. Who one Sunday morning and eating his cereal, he looked over at Leonard and Mary, saw the way she curled against him while cradling her cup of coffee, saw Leonard smile slightly and run a hand over her hair without looking up from the paper, and he felt a foreign pang in his chest. After a moment, he used all available evidence to define it as jealousy. He did not really want to smile idiotically at Penny and stroke her like a favored pet in front of their friends. However, if he had wanted to, he suddenly felt it was quite unacceptable that he was not free to do so.

"Excuse me," he said rather abruptly. Leonard and Mary looked up, startled, as he put down his cereal, stood up, and marched to the front door.

"Hey, Sheldon, where are you go-" Sheldon shut the door solidly the on the end of Leonard's inane questioning. If he had desired for them to know his whereabouts, he would have told them before departing, wouldn't he?

It was before 11:00. Sheldon risked harm to his person by knocking on Penny's door anyway.

Knock, knock, knock. "Penny." Knock, knock, knock. "Penny." Knock, knock, knock. "Penny." The door swung open, and Penny blinked up at him with tousled hair and a hand covering her yawn. She glanced past him, saw he was alone, grinned rather devilishly considering the early hour, and slipped a hand into the belt of his robe to pull him close so she could kiss him gently on the lips.

"Good morning, sweetie," when she had released him. She stepped back to let him into her apartment.

"Good morning, Penny," Sheldon replied dutifully as she closed the door. "I would like to know why you are ashamed of me."

She gaped at him. He took her silence as an invitation to continue.

"I assure you, I am a far superior choice for a mate than any of the evolutionary throw-backs to whom you have previously connected yourself. I am extremely intelligent. I am at the top of my chosen field. I am responsible. I am capable of providing both for myself and for any dependants who may present themselves in the future. I fail to see why you have not yet made a formal declaration or public presentation of our pair bond. I assure you, in a Darwinian sense, I am the most logical choice."

Penny furrowed her brow in an expression he had come to understand meant that she was translating his statement into words of smaller syllables that were easier for her inferior brain to comprehend. He occupied himself during his wait by imagining kissing the tiny wrinkle between her eyebrows.

"Okay, let me get this straight. You think that I'm embarrassed of being with you, and that's why I haven't said or done anything in front of the guys."

"Yes."

"But you want me to."

"I should have thought that was rather obvious, Penny," Sheldon said, trying not to grow frustrated with her impossibly slow comprehension level and managing it well by thinking about how lovely she looked with her face scrubbed clean and her hair like yellow silk around it. She narrowed her eyes at him.

"Sheldon Cooper, did you just ask me to be you girlfriend?" she asked with what sounded like shock. Sheldon winced at her word choice.

"Girlfriend is an entirely inadequate word, Penny. I do not wish to carry your books to second period or pass notes to you between classes. I wish to be your preferred companion, your partner in all things, as you are mine. That is, if you will please explain to me why you are ashamed of me, so I can repudiate your clearly false assumptions."

As he spoke, Penny's eyes began to sparkle, and were every shade of green at once. She put her hands on her hips and lifted her chin in a determined manner.

"Oh, I'll show you ashamed, sweetie. I'll just show you." She marched over to him, grabbed his hand, and practically dragged him across the hall to his apartment, where Raj and Howard (or rather, Howard with occasional whispered input from Raj) were now chatting with Mary while Leonard retrieved the first season of Battlestar Gallactica for their planned marathon. They all looked up expectantly as Penny chose a spot near the television for maximum effect.

"Does everyone see who I'm standing here with?" They all nodded, and Sheldon wisely chose not to undermine her authority over the room by pointing out the dangling participle at the end of her sentence. Penny nodded back at them.

"Good. Just so we're clear." Then, with great gusto, she grabbed Sheldon by both perfectly pressed lapels, hauled him against herself, and kissed him for all she was worth, and really, Penny was worth quite a lot. When she finally let go, Sheldon could barely stand up for lack of oxygen, and he was relatively certain his blood had abandoned his cranium for more southern geographies because he could not seem to form a coherent thought. He was vaguely aware of four people gaping at them in complete disbelief, but he couldn't rouse himself to care.

Penny took a deep breath, and sent Sheldon's already erratic heartbeat into dangerous arrhythmias by licking her lips hungrily before dragging her gaze away from his mouth.

"Is everyone clear on what just happened?" she asked the room. Four mouths snapped shut and four heads nodded vigorously in response to her no-nonsense tone. Sheldon thought of it as her teacher voice. Thinking such a thing did not help in regulating his heart rhythms.

"Does anyone have a problem with it? Before you answer, you should know that I will throttle with my bare hands anyone who says yes." No one said yes. There seemed to be several stammered, "no, no problems" and one or two "absolutely nots", but no yeses that Sheldon could hear.

"Good," Penny said, as if this settled the matter, and perhaps it did. "Alright. Well, carry on. Sheldon and I have a few things to talk about. In my apartment." With that, Penny laced her fingers with Sheldon's and began to walk briskly to the front door. Just before the door closed behind them, Sheldon heard Wolowitz's voice echo out of the apartment behind him.

"What the frak was that?"

What, indeed.

A/N: As always, reviews are loved and appreciated!