Disclaimer: I do not own The Big Bang Theory or any of its characters. If I did Sheldon/Penny would be so on. I do however take responsibility for any and all science errors.
AN: Spoilers up through all of season 3 as well as some hints of what may be happening in season 4 according to episode descriptions and a bit of poking around spoiler sites. It is really not too spoilery. You just have to know about Amy.
The Cooper-Fowler Relationship Fallacy
"Are you really going to ask Amy to marry you?" Leonard exclaimed staring at his roommate in horror.
"Is it not the proper social convention to propose to a woman with whom one is compatible after an appropriate courting period?" Sheldon asked with as much interest and passion as he would have discussing the weather.
Leonard felt the veins in his forehead begin to throb and forced himself to take a deep breath. "I thought the two of you weren't in a relationship?"
"We are not in a carnal relationship, if that is what you mean." Sheldon replied calmly. "But I don't see what that has to do with anything."
"You don't see-" Leonard gasped before stopping himself. "Then why would you ask her to marry you?"
"There are two reasons." Sheldon replied in a long suffering tone, frustrated that Leonard always seemed two steps behind. "First, the financial benefits afforded to married couples in the form of tax breaks and health insurance benefits are quite appealing. While I am not concerned with issues of money I have become aware that Amy's workplace offers significantly better dental insurance for their employees-"
"Dental insurance!" Leonard interjected in shock.
"Yes, Leonard." Sheldon said. "You know that despite my exemplary attention to oral hygiene I suffer from a regrettable-"
"I know you have bad teeth!" Leonard yelled, interrupting what would likely turn into a lecture about the evils of over-fluoridated water supplies in East Texas. "But what is the second reason?"
"You don't have to shout." Sheldon said disapprovingly, ignoring Leonard's glare. "The second reason really should be quite obvious. Entering into a marriage contract would prevent Amy's mother from constantly encouraging her to 'find someone.' Luckily my family gave up on the idea of setting me up with anyone after the disastrous blind date incident of 1999, but it would remove any further need for near strangers and even friends"-Sheldon gave Leonard a dark look-"to waste my time with talk of outdated human mating rituals."
Leonard fought the urge to strangle Sheldon. "Why would being married reduce the discussion of sex? I would think it would increase the frequency with which you were expected to participate in discussions relating to relationships."
"Oh, Leonard." Sheldon said with pity in his voice. "All anthropological evidence points to a significant decrease in sexual activity after marriage. How else would comedians make money?"
Leonard didn't know how much more of this conversation he could take. For someone who was so smart Sheldon sure was an absolute idiot.
"What does Amy have to say about all of this?" Leonard asked.
"Nothing yet. I am under the impression that it is standard for the man to surprise the woman with a ring before asking her hand."
"At least you have that part right." Leonard said with a sigh. He turned toward to door, finally having reached his mental limit. "I have to go."
"Where are you going?"
"To Penny's." Leonard said grabbing the his keys out of the bowl next to the door.
"Excellent," Sheldon said walking over to his desk. "Will you ask her what is a more appealing diamond shape? For the life of me I can't see why it matters if it is shaped like an oval or a pear. Honestly the whole custom is monstrous. Wasting all those diamonds, and for that matter precious metals such as platinum, on jewelry should be a crime. Just think of all of the scientific research that could be facilitated by the materials an average woman so cavalierly flaunts in the form of mere decorative baubles. "
"I'll ask her." Leonard agreed to get Sheldon to shut up. He hurriedly left the apartment, slamming the door behind him, before Sheldon managed to say anything else.
Sheldon sat in his seat, his computer in his lap as he scrolled through pictures of engagement rings. He was finding it nearly impossible to determine the appropriate diamond size to demonstrate a favorable social status. According to his research the size of the ring had some sort of effect on a woman's social standing. He was sure that Amy would be indifferent to the relationship between engagement rings and prestige but that her mother would expect an appropriate offering.
He was mentally constructing a formula to determine the maximum obtainable status with the minimum monetary input when his door slammed open. Sheldon jerked and looked up at the intruder. When he realized it was Penny he was genuinely pleased, sure that she would be able to tell him which ring to get.
"What the hell are you thinking?" Penny shouted.
Sheldon momentarily forgot all about engagement rings and flinched back into his seat, trying to put as much space as he could between himself and the irate woman standing in his living room. "I'm thinking that I don't like being yelled at. First Leonard and now you."
Penny silently opened and closed her mouth several times before closing her eyes and taking a deep breath.
Sheldon relaxed when he realized that she wasn't going to yell anymore. He watched her curiously. "Are you counting to ten?"
"Yes, Sweetie." Penny said more calmly. She opened her eyes and moved to sit next to him on the couch. "Sheldon, Leonard told me that you are planning to propose to Amy."
"Yes," Sheldon said turning his laptop to face her. "Did he also ask you about diamond shapes? Because I could really use some assistance."
Penny ignored the computer screen and stared at Sheldon in a way that made him slightly uncomfortable. "Leonard told me everything. He told me why you think getting married is a good idea."
"I don't think it is a good idea. It is a good idea." Sheldon said beginning to get irritated. "Entering into a marriage contract will provide both of us with benefits that we would not have were we to remain single."
Penny sighed. "Like what? Dental insurance? Sweetie marriage is about so much more than that."
"Like love?" Sheldon scoffed. "Romantic relationships do nothing but distract a person from reaching his or her true potential. Love as an impetus to marriage is a rather modern conceit that has led to a forty percent divorce rate in the United States."
"Sheldon, I'm not talking about romantic love. At least not the way you think I am."
"Then what are you talking about?" Sheldon asked.
"I'm talking about what the Ancient Greeks would call Agape." Penny said.
Sheldon blinked at Penny in surprise. He sometimes forgot that while she was was lacking an education and was no where near as smart as him, she was by no means stupid.
Penny rolled her eyes at the surprised look on Sheldon's face. "I'm taking acting classes. I don't know if you're aware but acting class is all about getting in touch with emotions and the various types of love were covered last week."
"That sounds like a monumental waste of time and money."
"Anyway," Penny said, "The point is that you don't need passion and lust for a marriage but you do need a love."
"I'm still not seeing your point." Sheldon said.
"Okay, answer me this: What will Amy do when you get sick?" Penny asked.
"I'm sure she will remove herself from the vicinity in order to avoid any contagions." Sheldon said as though the answer should be obvious.
"Exactly!" Penny cried in triumph. "When you are old and gray with a Nobel Prize up on the mantle who is going to sing you Soft Kitty and rub the Vick's on counter-clockwise?"
Sheldon stared at Penny, too ashamed to admit that he had assumed that she would be there to do those things. He really couldn't imagine Amy doing anything so personal. He had mentioned Soft Kitty to her once and she had not understood his interest in a song with such a juvenile rhyme structure.
"You need to find someone who not only understands how important your work is but who also understands how to truly love Sheldon the man not just Sheldon the physicist." Penny hesitated before continuing. "And most importantly you need to find someone who you don't just tolerate or respect but someone who you are willing leave your comfort zone for, at least far enough to take care of them a little too."
Sheldon just stared at her trying to imagine a future where there was no one to take care of him when he was sick. He didn't like the idea. Of course he didn't like the idea of taking care of anybody else either.
"I guess what I'm saying is I honestly don't think that you would have that kind of relationship with Amy. The two of you are too alike. You need someone whose weaknesses are your strengths and vice-versa."
The intense look on Penny's face was making him feel uncomfortable. It was like she was trying to make him understand by sheer force of will alone. Avoiding her eyes, Sheldon looked down at his computer screen and began to close the open windows. "I concede your point. Although I do not think that I will ever have the type of relationship that you described I can't argue with your assessment."
Penny sighed with relief. "Does this mean you aren't getting married?"
Sheldon nodded. He was still avoiding looking at her so he was surprised when he felt her throw her arms around him in a fierce hug. He stiffened up at the touch but didn't protest.
Sheldon tried to go to sleep after Penny left, but instead of calming him, his routines seemed to make him more agitated. As he lay awake he couldn't help but realize that there was only one woman outside of his family that had ever succeeded in drawing him willingly outside of his comfort zone. There was only one person in the whole world who he had ever sung Soft Kitty to. There was only one person who he had hugged of his own volition. Penny.
He wasn't entirely comfortable with the realization that Penny was the most important person in his life. She was more important to him than Amy, Leonard, or his mother. She even gave his Meemaw a run for her money. Sheldon wasn't sure when an uneducated waitress had become his best friend but it had happened and now he had to deal with the consequences.
Sheldon had trouble interpreting social situations but tonight it had been very clear that Penny did not approve of his relationship with Amy. She seemed to think that Amy held him back. He would never have seen it that way himself, but the more he thought about it the more he thought that Penny might be right. When he was with Amy they stayed completely entrenched in their comfort zones and while he might prefer that it hadn't been good for his work. When was the last time that an unexpected event had caused him to approach his work from a different angle? Like it or not a little spontaneity was good for his work. Just not much.
Making up his mind he sat up straight in bed and grabbed his cell phone. He dialed Amy's number and tried to ignore the spasms on the left side of his face as he waited for her to answer her phone.
"Sheldon, why are you interrupting my Stage N3 sleep?" Amy asked when she answered, bypassing a greeting.
"I have come to realize that I can not be involved in a relationship with someone who will not sing me Soft Kitty when I am sick." Sheldon said bluntly.
"Are you saying that you wish to terminate this mutually beneficial arrangement merely because I find your desire to be sung to an unnecessary emotional crutch better overcome than catered to?"
"Yes." Sheldon said. "And while you may be correct in your assessment, I like it when people sing me Soft Kitty and have no desire to give it up."
"If I may make a query? Outside of your mother, what adult woman would sing you children's songs?"
"Penny does." Sheldon said firmly. "And since I find it difficult to maintain very many friendships, particularly those with the opposite sex, I am choosing her."
"You are choosing your intellectually challenged neighbor over me?"Amy asked, a bit of incredulity creeping into her voice.
"Because she sings to you."
"Yes, goodbye." Sheldon said hanging up before whispering. "But mostly because I sing to her."