Disclaimer: The Big Bang Theory is owned, and is the property of many people, of which, I am not one.

A/N: I'm sure "The Prom Equivalency" will be an episode to launch a thousand fan fics, so I'm here to offer mine. The story is complete, but I will be posting it in chapters.

A/N: Not all the dialog is accurate to the episode. I've taken some creative license.

PROMises To Keep

1

Amy stood before the mirror in Penny's apartment, smoothing down the pale aqua fabric of her dress's skirt, fidgeting with the neckline. She'd never worn anything so revealing, and while part of her reveled in the image of seductress reflected back at her, her innate modesty made Amy feel as though she was standing there naked. What is Sheldon going to think? she wondered. Would he be oblivious of her clothing, as he so often was? Would he be appalled at her flaunting her cleavage? Especially in front of the males of their social group? Amy had dressed for Sheldon, but if she garnered a second look from her friends, she wouldn't object.

There was a knock on the bathroom door. "Ames? How are you doing in there? Do you need some help with your makeup?"

Taking a deep breath, casting one last glance into the mirror, Amy opened the door. "I would love your expert opinion on . . ." Before she could finish her sentence, the door was flung open and Penny stood in front of her, mouth gaping.

"Amy! You look beautiful! Look at you hiding that body away under all those layers!" Amy felt the beginnings of a blush and looked away. Penny's reaction was almost better than what she hoped Sheldon's would be. Almost. "What a great color on you!" Penny continued to enthuse. "Come on," she said, taking Amy by the wrist and dragging her into the kitchen. "The light's better out here. Let's turn this wallflower into a bouquet!"

"Don't get too carried away," Amy said, brushing her recently curled hair over her shoulder. "I want Sheldon to recognize me." She thought a moment, then added, "Although, if you want to make me the hottest woman at the dance—after you of course—I wouldn't object." Penny was biting her lip as she pulled out a compact of eye shadow.

"You'll be smokin'."

It was hard to sit still as Penny worked her magic, first with her eyes, then moving onto foundation and blush. "Are you going to get dressed soon?"

"In a minute," Penny said, her mouth hanging slightly open as she applied color to Amy's lips. "Someone was hogging the bathroom," she teased. "Would you like some gloss?"

Amy resisted the urge to shake her head while Penny worked on her. "Um, I better not. You know how Sheldon feels about lip gloss."

Penny took a step back, placing her free hand on her hip. "Yeah, I do. He says it makes your mouth look too slippery. Which is why I totally think you should do it. How do you think he's going to react to that dress?"

Looking first down at her exposed bosom, then back up at her lipstick-wielding friend, Amy felt herself frown. "That's just it. I don't know what he's going to say. I know what I'd like him to say. 'Wow,' or 'that's a nice dress, Amy,'" she said, slumping on the stool she was perched on. "Instead I'll probably get, 'What are you wearing?' And his voice will continue to raise into that affronted screech. Then he'll tell me to march back into your apartment and put something decent on."

"Got it all figured out, have you?" Penny said with a smirk.

"Come on, Penny. You know Sheldon! What do you think my chances are of getting a 'you look nice' out of him will be?"

Biting her lip again, Penny shot a glance at Amy, clearly trying to think of something positive to say. "Welllll, maybe he won't notice?"

"Which would be even worse," she sighed. Suddenly, Amy straightened her posture, sitting taller. "You know what? Screw Sheldon! I'm not going to have two disappointing proms in my life. He can take my appearance as it is, or he can leave it!"

"You go, Girl!" Penny said, as she reached for a tube of lip gloss. "Put this on. Sheldon Cooper isn't going to know what hit him."

xxxxxx

Sheldon stood before the mirror in his bathroom, working up the row of tiny pearled buttons on his tuxedo shirt. The suit purchase had cost him a fortune at the time of Howard's wedding, but he refused to wear a garment someone else had worn. Now look at him! Getting a second use out of an outfit he was sure would never see the light of day—or night as the case may be. It might see a third use some day, the voice in his head reminded him. Sheldon shook himself. He didn't need that thought plaguing him at this moment.

From the time this ridiculous notion of a prom had come up among his friends, Sheldon had had no peace. From the thought of all the physical closeness he would be forced to endure, to the mental image of Amy dolled up and expectant, his mind had room for little else. In a way, he was glad the fateful night had arrived, because now maybe he'd be able to concentrate on work once more.

He'd asked Amy what color her dress was, because Leonard told him men often tried to coordinate their cummerbunds to match that of their date's dress. He'd railed for a full ten minutes on how this was supposed to be a formal dance, not a wedding, as Leonard just shook his head and eventually left the room. Amy had tittered when he'd asked about her dress and coyly offered she wanted him to be surprised when he saw her the night of the prom.

Well, here it finally was, and including feeling annoyed, he also found himself beating back an army of butterflies in his stomach. He had to remember to tell Amy she looked nice, whether she did or not. Although how she couldn't look nice was beyond him. Amy always looked nice. Sometimes too nice, as he was discovering more and more.

Raj had been the first to walk him through prom etiquette, although he himself had never been to one. He claimed he was an expert compared to Sheldon, because he'd at least watched "Pretty In Pink." Then came Leonard who'd had some convoluted discussion with him about corsages. Even Wolowitz weighed in. As if he could give any useful advice. He purposely didn't tell his mother about the dance because she would want every detail. From what the decorations were like to what Amy and everyone else wore. The requests for pictures would be endless. Maybe if something from the photo booth the girls were planning yielded a positive result, he'd email it to her after the fact.

Sheldon had reached the top button and he looked up to see his face in the mirror. The harsh, florescent lighting was doing nothing for his visage. There were beads of sweat on his forehead and upper lip, glistening there as if mocking him. He'd made many a derisive comment about his friends actually getting caught up in the absurdity of a post-high school prom. And yet, here he was, so nervous his normally pale features looked positively bloodless.

Taking a tissue, Sheldon mopped his brow and lips and stared into his widened eyes with a stern expression, admonishing himself. "Get a hold of yourself, Cooper! She's nothing you haven't seen before!"

Sheldon checked his watch and realized he'd better get a move on. Leonard still needed to knot his tie, he had to make sure his flask was filled, and he had to practice sounding sincere when he told Amy her appearance was pleasing. It was just so hard to tell her she was attractive when her physical attributes came second to the beauty of her mind.

Stepping out of the bathroom, Sheldon was already pulling on his collar. He was sure when he'd purchased the shirt there had been plenty of room in the neck, but tonight everything seemed to be constricted from his shirt to his lungs, which couldn't seem to draw a decent breath.

Sheldon spotted Leonard by his computer and wordlessly handed him his tie. Standing, and heaving a sigh, Leonard took the strip of cloth and reached up to loop it around Sheldon's neck. Without asking, Sheldon bent his knees to facilitate the arrangement of his tie, but Leonard wasn't working on making a knot. He was staring at Sheldon as if he'd sprouted another head.

"Are you feeling okay?" he asked, scrutinizing his roommate.

Sheldon swallowed. "I'm fine. Why do you ask?"

Leonard returned to his task. "Well, for one thing you look like death warmed over."

"You can't warm up death, Leonard." Sheldon pointed out.

"Well, if it was possible, you're what it would look like. Are you that nervous about tonight? You really don't have to be," he said, wrapping the lengths of the tie around each other. "It's just us, looking a little fancier than we normally do."

That's what he was afraid of. He counted on Amy looking a certain way, under several layers. Most fancy dresses he'd seen seemed to go out of their way to showcase a woman's figure. Especially their bust. He didn't know if he could handle seeing any portion of Amy's bosom. Just the thought had him taking several quick breaths.

"Calm down! You're not helping things, here!" Leonard fussed some more then added, "If you're not going to learn how to do this yourself, they make some pretty decent clip-ons, these days."

Sheldon heard himself making some comment about Bruce Wayne and Alfred, but his mind was on auto-pilot as he went about the task of filling his flask with pomegranate juice. The sooner this night began, the sooner it would be over. And the sooner he saw Amy, the sooner he could stop envisioning her alluring form as if she were wrapped in tissue paper. Which brought up another mental image for him.

"Oh, dear Lord," he mumbled under his breath, licking dry lips and swallowing once more.

Sliding his arms into his suit coat, Leonard looked over at Sheldon, brow wrinkled in concern. "And just because all your friends are having sex, that doesn't mean you have to."

Sheldon's breath took another hit. "Why would you say that?"

Leonard was moving around, and his gaze wouldn't settle. "Well, prom night is when a lot of kids loose their virginity. Like I said, that doesn't mean you have to."

"But you said it like it's expected! A tradition! Like slow dancing, getting our picture taken together, being elected prom King. . . ." It seemed impossible for his heart to beat any faster, but Sheldon felt his speed up nonetheless.

"You sure you're okay? Because if this is causing you this much stress, you don't have to go through with it. I'm sure Amy would understand."

Sheldon closed his eyes, taking a deep breath. That was the trouble. He knew Amy would concede to his wishes just to make him happy, but in the process, she would sacrifice all the hard work she and Bernadette's had put in, just to accommodate him. He wasn't going to let her down.

"I'm fine. I'll be fine," he said, silently repeating the mantra in his mind as he slipped on his tuxedo jacket.

"Okay," Leonard said with a shrug, then a bright smile. "Here we go!" Opening the apartment door, they crossed the short distance to Penny's. As her door opened, Sheldon saw a blur of red which only vaguely registered with him must be Penny. Instead, his gaze was riveted on the second woman. She was barely recognizable as his girlfriend. Amy's hair was curled, falling in soft waves around her shoulders, her eyes accented with shadow and mascara. And there was the dreaded lip gloss, making her lips look all the more appealing.

But that wasn't the worst of it. Although her pale aqua gown was modestly cut, complete with a shrug that hid her slightly hunched shoulders, the sweetheart neckline revealed more of Amy's skin than he'd ever seen. He didn't count when she'd been sick. He'd been performing a duty. This was different. This was Amy dressing up for herself, and for him.

Amy's gaze traveled the length of him, and she was twisting slightly back and forth. "Sheldon, you look so handsome!"

Penny's arm was around her fiancé's shoulder in the remnant of the hug they'd just shared. "What do you think, Sheldon? Doesn't Amy look hot? That should put some starch in the upper fleurman."

Sheldon swallowed once more, feeling himself beginning to perspire. She looked amazing, but he couldn't tell her that because his voice had deserted him. Amy looked up at him expectantly, waiting for the compliment she deserved.

"I. . .I can't do this," he said, making an about face and marching back towards the safety of his apartment, all the while praying he hadn't ruined his relationship with Amy forever.