After winning the Nobel, it soon became apparent that Sheldon's life was irrevocably changed. He was beleaguered with job offers, research grants and requests for interviews and lectures. It seemed to him like the world was his oyster. After some thought, he decided that he wanted to move back to the States. Although his time in Germany had been productive, he had used it as a respite from his life. Now having achieved his dreams, he felt confident to go back and confront his past. But before he even left Germany, he found that life wasn't easier as a Nobel Prize laureate. He struggled to interact with the public and hired and fired three assistants in quick succession. Then he had an epiphany. At first, the thought seemed so radical that even he wasn't sure he could make it work. But with little to lose, he turned to the one person he felt had never stopped caring for him.
Penny was taken aback by Sheldon's offer. She had never envisioned herself in the role he proposed, part office assistant and part public relations director. But it made a weird kind of sense. After all, she already knew how he liked his food prepared, and how to strictly adhere to his set schedule. Sheldon was offering not only to hire Penny as his personal assistant, but also to allow her and Leonard to live with him. He had already purchased a gracious home of several thousand square feet on a secluded, tree-lined drive in Pasadena. Of course, he intended to hire someone who would be able to clean to his exacting standards. What he wanted Penny to do was to keep the refrigerator stocked, organize his wardrobe, interact with the media, schedule his interviews, and travel with him as she was able.
Since her acting career had never gotten off the ground, she was free to accept, and Leonard allowed himself to be persuaded to this plan after he saw how beautiful Sheldon's new home was. It even had a backyard. He had been wishing that Penny would quit working and stay home to raise their future children. Although Sheldon wasn't the means by which he had imagined accomplishing this goal, privately he hoped that living in the lovely and expansive home (that he could never have afforded on his salary) would help change her mind. Maybe having Sheldon around would even be useful to his career. He wasn't even jealous of the idea of Penny traveling with Sheldon, as long as it wasn't too often or for too long. After all, by that time, everyone in their little group of friends knew how Sheldon's relationship with Amy had imploded, so Leonard figured it was as safe as if Penny had gone to work for a gay man.
Penny threw herself into her new position with an enthusiasm that amazed everyone, including herself. As time passed, she began to realize that she had never been happier. Her new job was challenging, requiring a lot of mental and emotional effort. At the same time, she was still able to pursue her acting if she wanted, although by this point, she was reluctantly conceding that she may never be a Hollywood starlet. In her work for Sheldon, she got to travel all over the United States and Canada. While Sheldon gave interviews and lectured at symposiums, Penny explored whatever city they were in that day. She found herself absorbing the history and culture of the different places they visited. She didn't notice how Sheldon began to draw her out more and more. He was fascinated by the way her mind was developing and genuinely enjoyed her unique and unorthodox comments.
When they were on tour, evening were always the best time of day. Their usual routine was to lay on their respective beds in the hotel room, eating ice cream or popcorn while they watched some sci-fi series. Afterwards, they liked to discuss the show. Penny never hesitated to tell Sheldon what she did or didn't like, and she enjoyed critiquing the plots and characters. Sometimes, Sheldon even stayed up past his usual bedtime, distracted by his spirited conversations with Penny. She had an intriguing mind, though one he found unpredictable and motivated by emotion rather than logic.
It was only long-ingrained habit that now kept him from betraying his secret feelings for Penny. Ever since he had watched her from the stage in Stockholm, she had occupied his thoughts more and more. But she was married to his best friend—happily married, or at least, not unhappy. He had offered her the job and house out of purely selfish motivations. If he could never explore how he felt, never act on his desires, then at least he could keep her close and see her almost every day. Watching the awakening of her mind was sheer torture for Sheldon, as she grew more and more alluring to him with each passing day. But he had always been good at hiding his feelings, at least with emotions like love, which he used to think lessened a person. So he was able to continue to talk and joke with her like they were merely friends.
Whenever they returned home from a lecture tour, Penny fussed over Leonard. Secretly, she was trying to hide how little she missed him while she was away, and trying to compensate for the guilt that made her feel. They would make love, brief interludes that all too often left Penny unsatisfied, and then invariably, Leonard would start to talk about his work and how he was sure his big break was just around the corner. Penny started to realize that she used to sound exactly like that with her acting career. Ashamedly, she wondered if he had as little chance of realizing his dreams as she'd had of becoming a famous actress.
For two years after he won the Nobel Prize, Sheldon was on tour across the North American continent, lecturing and making public appearances. During that time, Leonard was also traveling more frequently. He was becoming obsessed with his latest research project, which he was conducting in collaboration with a physicist at MIT. Penny began to feel restless. Although she loved her job and the travel it entailed, something was missing from her life, and she often felt lonely without understanding why. One day, she decided to stop taking her birth control pills, a step she discussed with neither Leonard nor Sheldon. Within two months, she was pregnant and secretly hopeful that a baby would fill the emptiness she felt inside.
Both of the men in her life surprised her with their reactions. Leonard had been pleased, of course, but he wasn't nearly as excited as she anticipated. Lately, he had been spending more and more time at MIT, and he was increasingly distracted when he was home. He would stay up late, working on his research, and Penny rarely saw him anymore except those times when he would wake her up in the middle of the night with his hand sliding up under her negligee.
Perhaps she should have expected that Sheldon would become as fussy as a mother hen, but he still had the capacity to astonish her. He hired a nutritionist to prepare meals for Penny when she could hardly keep anything down due to morning sickness. He had the entire house baby-proofed by the time she was four months along, and he was constantly sending her links to articles about pregnancy and pre-natal development, to the point where he was driving her crazy. But he also rubbed her aching feet (while wearing latex gloves) and walked to the convenience store at three in the morning to get her antacids or Red Vines, which she suddenly couldn't get enough of. Sheldon had also shocked her when he declared he was finished with public speaking engagements for the present. He stated that he was going to be spending most of his time at home, writing a book on his proof of string theory.
In the middle of Penny's second trimester, soon after she found out she was expecting a girl, something happened which deeply disturbed Sheldon and marred the delicate balance of their three-person household. He had needed to fly out to New York for a joint meeting with his publisher, agent, and editor about his manuscript. Leonard was away at MIT again. Sheldon hadn't wanted to leave Penny by herself, but she was getting so sick of his hovering that she almost threw a vase at his head and ordered him out of his own home. Although he would never have admitted it, her hormone-fueled mood swings terrified him, so he left with a feeling of almost relief.
Unfortunately once he arrived in New York, he found out his meeting had been postponed. He was self-righteously indignant at being left cooling his heels. If Penny had been there, they could have gone sight-seeing together, but ever since she had announced her pregnancy, his concern for her health had caused him to forbid her to do any more traveling on his behalf.
He saw on Leonard's Facebook page that his friend was attending an inter-departmental mixer at MIT, very similar to the ones they used to attend together at Caltech. With nothing else to do and feeling perhaps a bit uncertain after his latest clash with a pregnant Penny, he decided to rent a car and join Leonard for the evening. In the back of his mind, he thought that his presence, that of a Nobel Prize laureate, might lend prestige to his friend's career.
Although Sheldon had sent a text message informing Leonard of his change of plans, he suspected that Leonard, for some reason, wouldn't really want him there. The diminutive physicist had been reticent about his professional life at MIT. Sheldon decided to be on his best behavior, which meant that he would refrain from telling the other science professors how badly flawed their research and methodology was. Really, he thought to himself, Leonard should appreciate the lengths I'm going to.
When he spotted his housemate in the crowd, Sheldon noticed that there was an attractive woman in a low-cut dress hanging on his arm. The woman leaned close to Leonard and seemed to laugh at something he said. At that point, Sheldon became convinced she was feigning her laughter, since Leonard was notoriously bad at telling jokes. When Leonard saw Sheldon making his way across the room toward them, he paled and pushed the woman's arm off of his dark-jacketed sleeve.
"Sheldon... what the hell are you doing here?" Leonard asked belligerently, his attitude bolstered by the glass of amber liquid he held in his hand.
"I decided to join you this evening. I texted you to inform you of my intentions," Sheldon replied innocently.
Leonard's companion interrupted. "Dr. Allison Werner," she purred, offering her hand. "I recognize you... you're Dr. Sheldon Cooper. I've heard so much about you."
"Not from me, you haven't," Leonard muttered under his breath. "Sheldon, this is Dr. Werner, my partner in my research on n-dimensional quantum gravitational effects."
Leonard watched, feeling more and more disgruntled as Alli made a valiant effort to flirt with Sheldon. He could have told her she was wasting her time. In fact, he would have made a point to do so earlier if he'd had any notion that Sheldon had planned to show up. He couldn't help acting cold toward Sheldon. If Sheldon began to suspect that Leonard and Allison were more than just research associates, Leonard knew he could end up in really hot water with Penny. Fortunately, Sheldon seemed oblivious as usual. He soon drifted off and got involved in a heated debate with a white-haired professor about the merits of string theory versus loop quantum gravity.
What Leonard didn't realize was that Sheldon was far from oblivious. Over the past two years, Penny had been teaching Sheldon a lot about social cues in an attempt to keep him from making embarrassing faux pas. He still had no instinct for social situations, but he had memorized a long list of non-verbal quantifiers (or, as Penny liked to call them, "tells") and their meanings. He knew that the way Dr. Werner was touching Leonard indicated a physically intimate relationship, and the thought sickened him. In fact, he couldn't stand the thought of interacting with Leonard the rest of the evening. He stalked off in a combative mood, soon finding the intellectual fight he was looking for. He tore into his opponent mercilessly, no longer caring how his actions might reflect on Leonard. In fact, he wished he could shred Leonard's current theories with the same derision. The only thing that stopped him was the thought of how Penny might react when she found out, as he was certain Leonard would tattle on him if he chose to publicly criticize his former friend's research.
Sheldon meandered through his meeting with his publishers the next day in a distracted haze. He nodded occasionally with no idea what he was agreeing to, and in truth, it hardly mattered next to the awful realization that Leonard was most likely cheating on Penny. The worst of it was that he felt partly culpable. He had only wanted to help Penny when he offered her the use of his home. Because of Sheldon's generosity, Leonard could afford an apartment near MIT, which enabled him to spend more time away from his wife. The thought still made Sheldon furious, but what could he do? If he asked Leonard to leave, surely Penny would go too. Having Penny move out was the one scenario he would fight against with every means at his disposal.
He had plenty of time to think on the six-hour flight home. The Sheldon of a few years ago would have obsessed over the details of his contract. Today, all he could think about was that blowsy tramp of a physicist laughing and touching Leonard's arm. His sleep last night had been fitful and not at all restive. As much as he wished he could blame his sleeplessness on Leonard, he knew it had nothing to do with his best friend. Then again, if he were honest with himself, it had been quite a while since Leonard deserved the right to that title. No, the reason his thoughts were in turmoil was because of Penny. He was a terrible liar and worse at keeping secrets, but he also had no hard evidence that Leonard had done anything wrong. If he told Penny anything of what he suspected, he knew it would only hurt her feelings. Beyond wishing to keep peace in his home, he couldn't stand the thought of breaking her heart. It pained him that she was so emotionally invested in Leonard, but he had with wrestled with those demons three years ago, and his conclusion still stood. All he could do was to choose to be a part of Penny's life, to be her friend. She had already made her choice, and it wasn't him. It would never be him. He felt a sudden pang in his hands, and looking down he realized he was gripping the seat rests so hard, they left angry red marks on his palms.