Penny thought Sheldon's suggestion was a joke. It had to be. There was no other way her brain could process his calmly stated proposition that she become a surrogate mother for his and Amy's test-tube baby. She couldn't imagine two people less suited to be parents. They wouldn't even admit they were dating, for crying out loud. So even though the next time he brought up the subject, it was in person and seemed not only sincere but almost humble, she couldn't come up with any other response than slamming the door in his face.
In retrospect, she probably shouldn't have told Leonard, but she thought he would find it funny: his crazy roommate, going off on some insane scheme. Instead, he got jealous. Jealous, like she had promised Sheldon something that belonged to him instead. It didn't matter to him that she had turned Sheldon down flat. All Leonard could think about was how much he wanted to see her pregnant with his child, and how she kept resisting his efforts to possess her more completely. The disagreement quickly escalated into a shouting match. It ended with Leonard storming out of his apartment while Penny went home to drown her problems in a bottle of wine, as she did more and more often of late.
The next evening, after Penny had suffered through a miserable day at work due to her hangover, Leonard showed up with flowers and that pathetically hopeful expression. She took him back, of course. It wasn't like she had any other likely prospects anyway. They were making out on the brown leather couch and Penny was looking forward to some emotionally-charged makeup sex, and that was when Leonard dropped the bomb. He'd gone to a bar last night, got wasted and apparently gone home with some skank whose name he couldn't remember. But it wasn't really cheating because he'd been drunk, right?
Penny wished she had a drink in her hand to throw in his face or maybe just to dull the pain. She recalled all too clearly when he'd come to her for advice on how to cheat on Priya and get away with it. Stupidly, she'd thought she was his one true love and he would never do that to her. Stupid, she realized, because that was exactly how things had gone with Kurt, six years ago. Leonard tried to argue that this fell under the rules of the beta test. He was sure he could fix the problem simply by promising not to do it again, but something had gone cold inside of Penny. She realized that this was who he was, and no matter how much he felt like he was in love, it wouldn't change his cheating nature. She told him it was over for good and ordered him out of her apartment. Leonard probably went home to mourn his misfortune and listen to his favorite emo CD's. (The second part she knew for sure; she could hear the music from across the hall.) Penny was mad that he had been unfaithful, but angrier still that he thought she would believe him when he swore it would never happen again. Once a cheater, always a cheater, she reminded herself.
Penny poured herself another drink, feeling like she needed it desperately. She'd had a boyfriend back in high school who'd had a temper. Ryan had hit her once, open-handed across the face, while they were fighting. Afterward, he had brought her flowers and begged for her to forgive him. Eventually, she took him back. The next time they argued, he gave her a black eye. There was no hiding it, and it had taken all of her mother's persuasive efforts to keep her dad from going to prison for manslaughter. He'd threatened to hunt the guy down and beat him to a pulp. Once Penny had dropped 4H and baseball in exchange for boys and cheerleading, her relationship with her dad had been strained and distant. That night, for the first time in years, Penny felt like her dad really loved her. It gave her the strength she needed to end the abusive relationship.
She never thought her relationship with Leonard was anything like that. He was sweet and nice, if occasionally petty and jealous. But he had changed after dating Priya. Priya was both smart and pretty, making both Penny and Leonard aware that he could do better. Penny wasn't getting any younger, and her acting career was going nowhere, so the beta test seemed like her last, best hope of having something to show for her life. Except now Leonard had a new self-confidence, and even though he still had feelings for Penny, the balance of power had shifted. He started acting like Penny was the one who was lucky to have him. More and more, he treated her like a trophy, showing nude photos of her to people who were barely acquaintances. With that attitude, perhaps the cheating was inevitable. A sexual conquest of another pretty girl was a validation of his ego. She had never cheated on a boyfriend, so why did she keep ending up with guys who cheated on her?
She spent the next few weeks living off of cheap wine and expired cheesecake from work, ignoring in equal measure Leonard's begging her to take him back and the bills piling up unopened on her counter. Lately she'd been spending more and more of her meager salary on wine and shoes: so what? She figured that all of her financial problems would be solved once she married Leonard. But now she was faced with a dilemma: take Leonard back in the full knowledge that he was a cheater, or move back home with her parents in Nebraska and essentially start all over again. She couldn't stomach either of those options.
She'd forgotten all about Sheldon's crazy plan until one night when they were doing laundry together. She had to admit, she missed those simpler times when they hung out in the basement and chatted over the hum of the machines. It was probably that wave of nostalgia that made her confess to Sheldon that she was so far behind on her rent and utilities that she might have to move back home. Predictably, he panicked at first. He hated change, especially when it was thrust upon him with no time to thoroughly plan for the event and invent scenarios which would cover every possible contingency. After he had some time to think about it, he again brought up the idea of her being a surrogate mother.
She stammered, blinking at him in shock. How on earth could he consider fathering a child when he couldn't even drive himself to work? She asked it aloud, and he seemed pleased by her question. He outlined an intensely detailed plan which gave her the option of continuing to provide child care for the infant while he and Amy were busy working.
She didn't respond; she couldn't. It was completely insane, and yet here she was, listening to his plans, or at the very least, not stopping him as he blathered on. A little voice in the back of her mind said that bringing a child into the world - especially an intellectually gifted one as she was sure that Sheldon and Amy's kid would be - was something worthwhile, certainly a better accomplishment than simply getting married.
It took a few more weeks for Penny to agree, but the deciding factor was the money Sheldon would be paying her. It was either that, or move back to Nebraska. So she told the two of them she would have a baby for them. Of course, once she did, Amy showed a disturbing fascination with the details of Penny's menstrual cycle. But in the end, all Penny would really need to do was lie on an exam table while microscopic, fertilized eggs were implanted inside of her. Sheldon had prepared a surrogate contract that was over two hundred pages long. She tried to read through it but ultimately gave up trying to decipher his legalese and just signed it.
Sheldon and Amy signed their own relationship contract and immediately began to look for a fertility specialist. After the first doctor had stared at them as if they were crazy and bluntly suggested they try the old-fashioned way of conception, they went to another doctor, and then another. Finally, they found one who was willing to accede to their demands, and Amy began the series of hormonal injections designed to stimulate ovulation. Penny later found out that the fertility treatment procedure placed such a great strain on relationships that many didn't survive the process. It wasn't Amy's fault that the hormones seemed to turn her into a raving maniac. Her wild mood swings were like nothing Sheldon had ever experienced, and he was soon flinching every time she walked into the room. She would often start screaming at him for absolutely no reason. (Penny could hear her from across the hall.) Sometimes, she would go over and try to calm Amy down, more out of sympathy for Sheldon than from any real desire to cross "Pregzilla", which was Penny's uncreative and very private nickname for the hormonal Amy.
Her crazy mood swings were also the final straw for Leonard, who had quickly moved on after Penny dumped him. He started dating Alex, who had worked briefly for Sheldon as his assistant and had moved on to an internship with a defense contractor. Alex had met Pregzilla Amy once, very briefly, but it made her feel sorry enough for Leonard to agree to let him move in with her. He was out within a week, leaving Sheldon to sleep in the metaphorical bed he had made.
Amy's first round of fertility treatments was unsuccessful, and she reacted badly to the unwelcome news. The doctor did his best to reassure her in a professional capacity, but his personal feelings were far less positive. He couldn't imagine why she was trying to bring a child into this bizarre relationship of hers. Her boyfriend not only didn't want to touch her, he hadn't even shown up for her latest appointment.
Amy was already furious with Sheldon for his no-show earlier that day, and learning that the attempt to harvest viable eggs from her had failed drove her into a seething rage. When she went to confront him, he retreated into his room, locking the door behind him. She had been standing outside his room, berating him through the locked door, when a strange whirring noise interrupted her. Moments later, strips of paper were shoved underneath the door. She picked them up with a strong desire to braid them into a rope that she could use to throttle her boyfriend.
"What's this?" she snarled.
"Apparently, you don't recognize our relationship agreement. I have shredded it," Sheldon replied. "You have two minutes to vacate the premises before I place a domestic disturbance call to the local police."
Amy fumed and ranted until the very last second, and then she stormed out of the apartment, slamming the door so hard that a number of knickknacks fell off the wall and bookshelves. Sheldon crept cautiously out of his room after another twenty minutes. He was seriously considering getting a restraining order against her, but he hoped it wouldn't be necessary. The relief he felt was so enormous that he couldn't believe he had lived with so much stress for so long. It was partly his fault, he was forced to admit. He had been so sure that both he and Amy were reasonable people who could find a rational solution to any problem. But apparently, she hadn't been able to rise above her emotions, and he knew that hiding in his room wasn't really a logical reaction either. It was an emotional one. He had been scared and intimidated. The only conclusion he could reach was that he was never going to attempt a relationship of a romantic nature again.