It could be that they entered into a marriage of convenience for some reason, like Penny needing to get health insurance through Sheldon's job. But as they keep it secret, they start to develop real feelings for each other over time. They would have to sneak around, which could lead to some comical and also some really sweet moments. For example, they might have secret dates at Sheldon's apartment when everyone else is out, and slowly discover new things about each other that they never knew before.
Perhaps there was a scientific experiment gone wrong that required them to be legally married for a short period. They decided to keep it secret to avoid the ridicule and confusion of their friends. As they go through this strange situation, they find that they actually complement each other in ways they hadn't realized. Sheldon might introduce Penny to his scientific world in a more intimate way, and Penny could help Sheldon understand more about the real world and emotions. This could lead to a deeper connection between them, all while trying to keep their marriage under wraps from Leonard, Howard, Raj and the others.
Well, considering the popularity of the characters Penny and Sheldon, it's very possible that there is a 'penny and sheldon secretly married fanfiction'. Many fans enjoy imagining different scenarios for their favorite characters. They might want to see how these two very different characters would handle a secret marriage. You could start your search by using specific keywords related to the show and the relationship in the search bar of fanfic websites.
One common plot is how they adjust to living together as a married couple. Since they have such different personalities, it can be really fun to read about how they deal with daily life, like Penny trying to get Sheldon to be more social or Sheldon getting Penny interested in his scientific hobbies.
The contrast between their characters. Penny is outgoing and social, while Sheldon is introverted and geeky. Their marriage in fanfiction allows for a lot of humorous and heartwarming interactions as they navigate living together.
Some fanfictions might explore how they handle family - related matters. For instance, stories about them deciding whether to have kids or how they would raise children given their very different backgrounds. It could be really interesting to see how Sheldon's scientific mind and Penny's more practical approach would come together in parenting.
In some fanfiction, they might face challenges from their friends. For example, Leonard could initially have a hard time adjusting to the idea of Sheldon and Penny being married. But as time goes on, he realizes that they are actually good for each other. Also, their marriage could lead to some really funny situations at home, like Sheldon trying to understand Penny's love for shopping and Penny trying to tolerate Sheldon's obsession with the perfect seating arrangement in their living room.
You can try fanfiction websites like Archive of Our Own (AO3) or FanFiction.net. These platforms usually have a wide range of fanfiction works, and you might be able to find some about Penny and Sheldon getting married there.
Sheldon might become more empathetic. Being married to Penny, he is exposed to her emotions more often. For instance, when Penny has a bad day at work, Sheldon has to learn to comfort her, which is something he wasn't very good at before. So he starts to develop his emotional intelligence.
In fanfiction, a baby for Sheldon and Penny could be a catalyst for personal growth. Sheldon, who has always been set in his ways, would be forced to adapt. He might start to understand emotions better as he experiences the love for his child. Penny, too, would grow as she takes on the role of a mother. The baby's presence could also change the social fabric of their community. Neighbors might become more involved, and there could be new storylines centered around the baby's daycare, school, and extracurricular activities. It would be a whole new world for Sheldon and Penny, full of both challenges and heartwarming moments.
One possible plot could be that they got married on a whim during an undercover mission in a foreign country. They keep it a secret because they're not sure how their superiors and colleagues would react. As the story progresses, they struggle to balance their secret married life with their work, and there are close calls where their secret almost gets revealed.
In a possible plot, Voldemort is actually being controlled by a darker force all along. Harry discovers this and finds a way to free him. In the process, they develop an unexpected bond. They decide to get married secretly as they know the world won't understand. Their relationship then becomes a catalyst for changing the power dynamics in the wizarding world. They have to deal with enemies who want to use their relationship against them and friends who are shocked and confused by their union.