Author's Note: I finally wrote a TBBT fic that includes all the main characters instead of just Sheldon and Amy, haha. I had a lot of fun writing this story. It was originally going to be a oneshot, but since it was already fairly long even before it went through major revisions, my beta reader suggested that I break it up into several parts, which I agreed. So, this is going to be a four-parter.

Disclaimer: The Big Bang Theory © Chuck Lorre and Bill Prady

Amy was behaving like an overactive child.

A rudimentary and rather clichéd metaphor, but it truly was the most accurate comparison Sheldon could think of in this moment. His eyes bobbed in rhythm with Amy as she rapidly hopped up and down in place beside him. Her hair jostled against her shoulders, and she wore an enormous grin that never wavered. She didn't even seem the least bit winded when she at last stopped jumping and turned to Sheldon. His body automatically jerked backwards.

"Sheldon!" she said in excitement.

He furrowed his eyebrows. Why is she shouting? I'm standing right next to her. "Amy," he replied hesitantly.

Amy's smile still didn't falter, and her eyes were now gleaming behind her glasses. Good Lord, she isn't going to start crying, is she? It was alarming how quickly her emotions changed, not to mention very difficult to keep track of.

"You…" she started, her voice cracking slightly. She cleared her throat and began again. "You really did all of this for me?"

Sheldon tore his eyes from Amy to look at all of his friends scattered about his apartment. A colorful banner with the words, "Happy Birthday" written in all caps hung across the window behind them. Raj wore a bright blue, cone-shaped party hat and held a beer bottle, while Penny and Bernadette each held a glass of champagne in their hands.

Of course, Sheldon had wanted no part in this party planning scheme, but when Penny had threatened to throw one of his model trains out the window if he didn't help, he'd had no choice but to concede. He'd been instructed to keep Amy busy for an hour, and thankfully, that task proved far easier than decorating the apartment.

Since it was Sunday, he'd accompanied Amy to the mall, where she'd purchased a bottle of perfume. She claimed one whiff of it would drive Sheldon "wild with desire," which had rightfully earned her an obligatory look of derision coupled with a soft snort for impact.

Now, here they were, with Amy staring at him, eagerly awaiting a response to her question, the answer to which should've been obvious to her. Does she not know me at all?

"No, of course not," he said at last. "I had nothing to do with this."

Amy immediately frowned, and Penny groaned loudly.

"Sheldon," she chided.

He looked over at the blonde, who had the most unpleasant of looks on her face, though he truthfully couldn't fathom why.

"What?" he asked.

"What do you mean what?" she demanded. "How could you say you had no part in helping plan your girlfriend's surprise party?"

"Well, to be fair, he really didn't help," Leonard said. "All he did was rant about how surprise parties are 'an utter waste of time' and that the element of surprise does horrible things to a person's cardiovascular system—"

Penny leaned in towards Leonard, placing a hand on his shoulder. "Sweetie," she said.

Leonard glanced at her. "Yeah?"

"Shut up," she said with a tight smile, patting his shoulder twice before releasing him.

"Right," Leonard said simply.

Sheldon stared in dismay. Leonard was so "whipped" that it was quite literally a pathetic sight to see.

"It's all right, Penny," Amy said. "After all, it was foolish of me to think that my boyfriend of all people would actually care enough about me to put in the time and effort into planning such a thoughtful birthday festivity for me."

There was a brief silence, until Wolowitz raised his eyebrows and loudly sucked in air through his teeth.

"Ouch. You realize, Sheldon, that if you and Amy were having sex, you totally wouldn't be getting any tonight."

Bernadette smacked her husband's chest with the back of her hand.

"What? It's not like they do it anyway," Howard said as Bernadette glared at him.

"Well, regardless, I still appreciate the lengths the rest of you went to in order to put this party together for me," Amy said, a grin slowly returning to her face. "No one's ever thrown me a surprise party before."

"Which is all the more reason you deserved one," Penny said. "We all care about you and we want you to enjoy yourself tonight."

"Thank you, bestie," Amy said sincerely. "So how about we break out the booze and get this party started?"

"Finally," Koothrappali exclaimed as he took a swig of his beer and walked over to the bookcase. "Time to get crunk!"

He turned on some music, and an annoyingly upbeat pop song blasted through the speakers. Amy clapped her hands together and crossed the living room to get herself a drink. Penny and Bernadette joined her, while Raj and Howard started awkwardly thrusting their bodies while making strange facial expressions.

Sheldon stared out at the scene before him. This was going to be a long, long evening.

Forty-five minutes into the party, Amy had ingested one glass of wine and was currently working on her second. If Sheldon were a proper judge of such things, he would probably have deemed her as "tipsy." Raj, meanwhile, was completely intoxicated and giggling like a little girl while he chatted with the women.

Sheldon sat in his spot, watching the four of them as they socialized in his kitchen. He kept his gaze on Amy. He noticed that the effervescent smile had returned to her face. She looked positively radiant and happy, while Sheldon, on the other hand, couldn't have been more miserable. He couldn't stop thinking about what she had said about him not caring about her. The more he thought about it, the worse he felt.

Why do I feel…guilty? I've done nothing wrong.

"Having fun?" Leonard asked, taking a seat in the beige chair near the couch.

Sheldon snapped out of his musing. "What kind of question is that?"

"So that's a no then," Leonard concluded, leaning away from him and taking a sip of his beer.

Sheldon looked back at Amy. She was laughing from something Penny had just said. The music blaring at an obscenely high decibel made it harder for Sheldon to clearly hear her laugh, but with his Vulcan hearing he was, of course, still able to pick it up, rich and delightful as ever. She was obviously enjoying herself. That was a good sign.

Then why can't I seem to shake off this feeling of guilt?

He couldn't just ignore the feeling. It was eating away at him like an alien parasite slowly feasting on his organs. He needed to get rid of it somehow, and in order to do that, he knew he needed to take action. He had to show Amy that he did, in fact, care about her, much more than she knew.

But how?

He realized that this was the kind of thing Leonard might be able to weigh in on. After all, Leonard always seemed to be screwing things up with Penny, yet they were still together in spite of it all. For the time being, at least.

"Leonard," Sheldon said, shifting his body to face his roommate. "I have a relationship question for you."

"Oh, dear God," Leonard said.

"Excuse me. What is that supposed to mean?" Sheldon asked.

"Nothing. What's your question?"

"Well…just out of random curiosity, do you regularly express your feelings towards Penny through arbitrary romantic gestures, such as purchasing her flowers, complimenting her, or cuddling with her?"

Leonard's eyebrows scrunched downward as his mouth contorted into some bizarre geometrically-disproportionate semicircle. "Uhh…to answer those in order, occasionally, all the time, and only when she lets me."

"Interesting," Sheldon said, settling back against the couch, only to move forward again a mere second later. "And how does she generally react to those gestures?"

"Well, she'll usually thank me and tell me how sweet I am, or sometimes she'll reciprocate by giving me a compliment or even offering to pay for dinner once in a while."

"I see," Sheldon said. "And how often are these romantic overtures exchanged?"

"Look, Sheldon, if you're trying to figure out how to be more intimate with Amy without breaking your weird germaphobic lifestyle, I suggest you stop asking me personal questions about my relationship and just watch a couple of chick flicks. Trust me, they'll teach you how to be the ideal boyfriend."

Sheldon furrowed his eyebrows. What is he implying? That I'm not already an ideal boyfriend for Amy? I'm Sheldon Cooper. That, alone, should be enough.

"In fact, if you want, Penny could loan you The Notebook," Leonard went on. "Although, I gotta warn you, that one's a real tearjerker. Between that and A Walk to Remember, I went through an entire box of tissues that night."

Sheldon stared at Leonard, astonished. "What makes you think I'm interested in being more intimate with Amy?"

"Well…are you?" Leonard asked.

Sheldon looked at his girlfriend. She was listening intently as Bernadette told them an anecdote about the latest encounter with her over-sized mother-in-law. Howard, who'd since joined the group, stood beside her with his arm wrapped around her waist.

Remarkable. Even the small-minded Wolowitz knows the precise combination of when to give his significant other physical affection and just the right method to use.

Sheldon was beginning to think that it wasn't something learned, but rather innate. After all, if someone with only a master's degree could figure it out, then it must've been based on instinct rather than through social conditioning.

Or perhaps it was a bit of both.

Sheldon's gaze wandered back to Amy. She raised the glass of wine to her lips and took another sip. He hated when she drank alcohol, but he noticed that she seemed to be taking her time tonight. It seemed as though she didn't want to be so inebriated to the point where she couldn't remember the events of this evening, a night spent with her closest friends, all of whom cared about her deeply.

And then there was Sheldon.

He suddenly felt a tight swelling in his throat. He swallowed, but the dry, tightening sensation only seemed to worsen as he continued staring at her. His eyes followed the exuberant look on her face, a look he, himself, hadn't put there.

He groaned softly to himself as the pang of guilt struck him once more.

"So, birthday girl, what do you want to do now? Maybe play a fun party game?" Penny asked.

"Hmm," Amy hummed, glancing around at the circle of friends. Strangely, her eyes landed on Raj, who was still clutching a beer bottle in his hands. Amy's eyes lit up with an idea. She leaned towards Penny and whispered something in her ear.

Penny's eyebrows furrowed. "Really? That's the game you want to play?"

"Yes, I've never played it before, and I've always wanted to," Amy said.

"Well, I've played it too many times, but not since like, the seventh grade," Penny said.

"What game?" Leonard asked, getting up to join the group.

Penny looked at him. "Spin the Bottle."

Six pairs of eyes slowly locked onto Sheldon. His own eyes widened as the reality of what that meant abruptly sank in. His heart slammed unmercifully in his chest as his blood ran cold in his veins. He stared back at all of them one by one until his terrified gaze inevitably ended up on Amy.

He'd heard of that game, of course. His twin sister used to play it with her friends on many occasions when they were young. He knew exactly what it entailed: sitting in a circle on the dirty floor, spinning an empty bottle and kissing whomever it landed on, while everyone else gaped and hollered at them like feeble-minded simpletons.

He would not be having any part of it.

"No," he declared.

That troubling frown returned to Amy's face. He seemed to be doing an outstanding job at making her unhappy lately. "Why not?"

"Why not? Where do I even begin?" Sheldon asked, rising to his feet and walking over to everyone. "Would you care for an itemized list sorted by order of importance?"

"Oh, God, Sheldon, cut the crap already and let Amy have some fun," Penny said. "This day isn't about you."

He frowned, taken aback. "I never said it was."

"You didn't have to. The fact that you're acting like a total ass says it all."

Sheldon stared at Penny. "I am by no means behaving like a total…" He trailed off and cleared his throat, deciding to direct his attention to Amy, who placed her glass of wine on the kitchen counter and folded her arms over her chest defiantly. "Just answer me this, Amy. What good do you think will come of playing that game? Chances are you'll have to kiss someone other than myself, which you know is in direct violation of the Relationship Agreement."

Amy didn't say anything. What could she say? His logic was irrefutable. Sheldon could feel a smirk coming on, but he restrained himself, for he didn't want to appear too cocky. Still, he was confident that she knew he was right. He always was.

"Furthermore," he went on, just to be certain that she would agree, "you may have to kiss Howard, which would be a horrific thing to witness, let alone experience." He looked at Bernadette. "No offense."

"Excuse me," Howard scoffed. "You just insulted me, not her."

He purposely ignored Howard, who was now releasing a heavy sigh and mumbling something about how Sheldon was a "son of a bitch."

"So, Amy, is that really a risk you're willing to take?" Sheldon asked.

"I'll admit that you raise a valid point, but quite frankly, I don't care," Amy said. "If I have to kiss Howard, I'll suck it up and do it. I'm sure it won't be any worse than having to swap saliva with Leonard." She flashed a look at Penny. "No offense, bestie."

"What the hell? I'll have you know I am an excellent kisser," Leonard said, turning to his girlfriend. "Tell her I'm not a bad kisser."

Penny smiled brightly and patted his back. "You're not a bad kisser. In fact, you've really improved a lot over the years."

Leonard smiled at first, but as the rest of what she said seemed to sink in, he frowned, not looking the least bit comforted.

"Are we going to do this or not?" Raj asked. "'Cause if we are, I need to put on some lip balm. Soft, kissable lips don't just happen, you know."

"Well? What do you say, Sheldon?" Amy asked.

Sheldon blinked. He had not anticipated this. Apparently, a new tactic was required. He straightened his shoulders and crossed his arms.

"You can't make me play."

"Fine," Amy said. "If you don't want to play, then you can just sit back and watch as the rest of us do."

"Watch as you exchange germs with everyone? I don't think so," Sheldon said, uncrossing his arms.

"Oh, grow up, Sheldon. Stop trying to control Amy," Penny snapped.

"Yeah, dude, don't be a party pooper," Raj added.

Sheldon drowned out their petty remarks and kept all of his focus on Amy. She seemed so unhappy. The guilt he'd been fighting off returned. Was he being fair? Should he give in? He did want her to enjoy herself, but why did it have to be this game of all things?

What if I have to kiss someone else?

The notion of having to kiss Amy in front of everyone was shocking enough. Yet, he could admit—to himself at least—that he wouldn't mind feeling her lips against his again. After all, it had happened before, and he didn't necessarily object to the idea of having it happen again. In fact, lately, it was something he'd been considering more and more. But to have to kiss someone who was not Amy? The mere idea of that was abhorrent.

But it's what she wants. It's her birthday. As her boyfriend, I should give her what she wants.

He stared into Amy's eyes, searching for the right answer. His conscious was screaming at him, pulling him in two different directions: go along with it for the sake of Amy's happiness, or sit by and watch as they play the game without him.

Amy looked away from him, frowning in obvious disappointment.

He was hit with a rush of panic.

Maybe I can do this.

The moment he thought that, though, his panic worsened.

Oh, God, what am I thinking? I can't do this. I won't do this.

No.

No.

Absolutely not.

NO.