I would say it's not common. Fanfiction often gravitates towards romantic or heroic storylines that build on the existing characters' relationships in a positive way. The concept of Ben getting Gwen pregnant is quite unorthodox given their kinship. It might exist in some very niche corners of the fanfiction world, but it's not something that you would come across often compared to other more popular fanfiction topics like the main characters' adventures or their more typical romantic relationships.
It's not common at all. Most fanfiction tends to follow the more positive and popular pairings or storylines within the fandom. The idea of Ben getting Gwen pregnant is rather controversial due to their family relation in the source material. Writers usually prefer to write about things that are more in line with the general mood and values of the fan community, which doesn't really include this kind of rather odd and potentially uncomfortable scenario.
In fanfiction, a story about Gwen being pregnant in the Ben 10 universe could take many directions. It might explore how her pregnancy affects her role as a hero. Maybe she has to take a break from fighting aliens and focus on her well - being and the baby's. This could also lead to new character developments for Ben as he has to step up more in her absence.
One possible storyline could be that they face a lot of family drama. Their families might be shocked and have different reactions, some may be supportive while others are against it. It could also explore how Ben and Gwen deal with the sudden responsibility and how it changes their relationship from just being cousins to co - parents.
Well, family - friendly themes in such fanfiction could include the support they receive from their friends. Their alien - fighting days might take a backseat as they focus on the upcoming addition to the family. Also, there could be themes related to the anticipation and excitement of becoming parents. They could be shown preparing for the baby, like setting up a nursery or learning about parenting. It could also explore how their relationship as cousins changes in this new context, but still in a positive and appropriate way.
There might be some out there, but it's important to note that in the official Ben 10 universe, such a concept is not part of the canon. Fanfiction often takes creative liberties. However, you should be cautious when looking for it as some fanfictions may not adhere to appropriate standards.
In the fanfiction, the relationship between Ben and Gwen could change in a complex way. The news of the pregnancy might initially cause some tension and fear between them. But as they gradually accept the situation, they start to grow closer. They might start to see each other in a new light, not just as partners in adventure but as life - long partners in raising a child. This could involve a lot of communication, understanding, and compromise as they navigate through this new chapter of their lives together.
A common theme is adventure. Since the original show is about Ben having adventures with his alien forms, fanfictions often continue this trend with Gwen also being involved in exciting escapades.
It's highly unlikely to be a common type of fanfic. Fanfiction often aims to build on the existing story, characters, and relationships in a way that is somewhat believable or at least in - keeping with the spirit of the original work. A concept like 'ben impregnates gwen' is so far - fetched and often against the grain of the normal portrayal of the characters that it would be an outlier rather than a common type of fan - created story.
I don't recommend delving into the themes of lemon fanfiction. But for regular Ben and Gwen - related fanfiction, themes can be things like loyalty. They are always there for each other during their battles against aliens. Another theme could be their evolving relationship as they get older and face more complex situations in the series. Also, their individual character development, like Ben becoming more responsible and Gwen getting stronger with her powers, are often explored.
Common themes in Ben and Gwen romance fanfiction include the idea of secret love. They might keep their feelings hidden from the rest of the family or friends. Also, the theme of self - discovery is present. As they explore their romantic feelings for each other, they also learn more about themselves. And sometimes, there's a theme of sacrifice, where they are willing to give up something for the sake of their relationship.
One common theme is growth. Both Ben and Gwen grow as individuals and in their relationship. Another theme is friendship, as their bond is often a central part of the stories. Adventure is also a big theme, since they are from the Ben 10 universe and usually go on exciting adventures together.