The appeal of Mavis and Jonathan kiss fanfiction lies in the fact that it can fill in the gaps that the original story might have left. Maybe the original didn't show enough of their romantic moments. Fanfiction writers can then create these beautiful kissing scenes that satisfy the readers' desire for more romance between the two characters. Moreover, it can be a form of escapism for readers who love their relationship, as they can immerse themselves in these fictional, romantic scenarios.
You can try looking on fanfiction websites like Archive of Our Own (AO3). It has a large collection of various fanfictions, and you might be able to find some great mavis and jonathan baby fanfiction there.
One interesting story could be about Mavis and Jonathan taking their baby on a magical adventure through the forest near their home. The baby discovers new magical creatures and they all have to work together to protect the forest from a dark force.
One great piece of Mavis and Jonathan kiss fanfiction is 'A Moment in the Moonlight' on FanFiction.net. It beautifully captures their relationship and the emotions behind their kisses.
Maybe Mavis, in her exploration of different realms, ends up in the ninja world. She gets into trouble and Naruto comes to her rescue. Naruto is intrigued by her magic and Mavis is impressed by his ninja skills. This encounter plants the seed for their relationship that eventually leads to marriage.
I'm not sure exactly who Jonathan Wamback is without watching the story. He could be an ordinary person with an extraordinary story, or someone well - known in a specific community or field.
Naruto has shown incredible feats of strength, speed, and endurance. He has defeated some of the most powerful villains in his universe. But Mavis is no slouch either. Her Fairy Law is a very powerful spell. If we consider their growth potential, Naruto has the ability to constantly get stronger by unlocking new forms of his power, like Sage Mode and later the forms related to the tailed beasts. Mavis, on the other hand, has a deep knowledge of magic that could potentially allow her to counter any of Naruto's attacks. It really depends on the situation, the location, and how well they know each other's abilities.
One of the main characters could be Wayne, the werewolf. He and his family could bring some fun and chaos to the story. Maybe they come to visit Johnny and Mavis, and the werewolf pups accidentally cause some trouble in the baby - proofing of the house. Also, Griffin, the invisible man, could be there. He could use his invisibility to play pranks on the couple during their pregnancy, but also be a good friend when they need help.
Their relationship would likely become more centered around the baby. They would have less time for just themselves and more time taking care of the baby's needs.