They could love all kinds of fanfiction. Maybe they're into the fanfiction based on science - fiction shows, like Star Trek or Doctor Who. These shows have vast universes that can be explored in many different ways in fanfiction.
Davis and Kari could be just two individuals with a passion for fanfiction. Maybe they love the creativity that fanfiction offers. Fanfiction allows them to explore different versions of their favorite stories, characters, and universes. It gives them a chance to engage with the source material in a more personal and imaginative way.
Another theme is family. They might be starting a family or dealing with their extended families in these stories. For example, how they introduce each other to their relatives and the reactions they get.
Yes, there are. You can find some on various fanfiction websites. Some might focus on different adventures they have and how their relationship develops to the point of that kiss. It could be a really sweet and romantic take on their characters.
One interesting Digimon TK and Kari baby fanfiction could be where they discover a new Digimon egg while on an adventure in the Digital World. The baby Digimon that hatches has unique powers that TK and Kari must help it control.
One popular Davis and Kari married fanfiction is 'Our New Beginning' which focuses on their life after marriage, dealing with challenges in a digital world they often face in the original series. It shows their growth as a couple.
I'm not sure exactly which 'tk and kari married' fanfiction is out there. You could try searching on fanfiction websites like Archive of Our Own or FanFiction.net. Just type in 'tk and kari married' in their search bars and see what comes up.