One common theme could be the theme of responsibility. If we consider the 'pregnancy' as a symbol, it could be about Dipper and Mabel learning to be more responsible for their actions or for something new in their lives, like taking care of a new pet or a new magical item in Gravity Falls.
The theme of growth is also quite common. Their 'pregnancy' could signify their personal growth. They are moving from one stage of their lives to another, and they have to face new challenges and learn new things. For example, they might be growing out of their old habits and becoming more mature, and the 'pregnancy' concept is used to represent this internal change.
One good theme could be about family support. For example, how their family and friends react to the news of Mabel being pregnant and how they all come together to support her and Dipper. Another theme could be the growth of Dipper and Mabel as they prepare for a new addition to the family, learning new responsibilities.
One common theme could be the exploration of a different kind of relationship between them, perhaps in an alternate universe where the normal sibling boundaries are a bit more blurred. Another theme might be the idea of a first kiss and the emotions that come with it.
One common theme is sibling adventures. Since Dipper and Mabel are siblings, a lot of fanfictions explore their relationship further while they go on different adventures in Gravity Falls. Another theme is mystery - solving. It's in line with the overall tone of the show, so fanfic writers often create new mysteries for the twins to solve.
One common theme could be role - reversal in their personalities. For example, Dipper might be more carefree and Mabel more cautious. Another theme could be exploring a different kind of relationship dynamic between them, like a more romantic - friendship hybrid.
There could be. Some fanfiction authors might write about Dipper and Mabel in a 'pregnant' situation in a metaphorical sense. Maybe they are carrying the weight of a big responsibility, like taking care of a new magical discovery in Gravity Falls, and the author uses the 'pregnant' concept as a creative way to show that burden or new phase in their lives.
A common theme is friendship. Despite their differences, they learn to be friends. Another theme could be growth. For instance, Pacifica may grow to be more accepting of Dipper and Mabel's wacky ways, and Dipper and Mabel may grow in understanding of Pacifica's background.
One possible theme could be exploring the darker side of sibling relationships. Maybe it delves into how misunderstandings or power imbalances within a family can lead to such a disturbing situation. However, this is a rather unorthodox and potentially disturbing concept for a fanfiction.
One common theme is friendship. Even though it's a love game, their strong bond as siblings and friends is often explored. Another theme is mystery, as the nature of the love game itself is usually a mystery they have to solve.
A common theme is growth. Since they are teenagers, it often shows how Mabel and Dipper are growing up, facing new challenges, and becoming more mature.
There might be some out there. Some fanfiction writers may explore the concept in a non - inappropriate way, like focusing on a future where they are expecting in a very innocent, family - centric story setting. But it can be hard to find among all the fanfiction content.