There might be a fanfic where Jessie and James get stranded on an island. This would force them to rely on each other in new ways, and perhaps develop deeper feelings for one another as they struggle to survive and find a way back home.
You can start by looking on fanfiction.net. It has a large collection of Pokémon - related fanfics, including many about Jessie and James. Just use the search function and type in 'Jessie x James' to find relevant stories.
They might love fanfiction because it offers new perspectives on their own lives. In fanfictions, their characters can be developed in ways that the original show might not have explored fully. For instance, they could be portrayed as more complex individuals with deeper backstories.
One common theme is unrequited love finally being realized. For a long time in the Pokémon show, their relationship was more of a comical partnership, but in fanfiction, the kiss can be a moment of that underlying love coming to the surface.
Well, there is definitely some 'jessie and james kiss fanfiction' around. If you're into more romantic - themed ones, you might find some where the kiss is a turning point in their relationship. Others could be more comical, like it happens by accident during one of their zany schemes in the Pokémon series.
In fanfiction, the jealousy of Jessie towards James might be a creative way to explore their characters more deeply. It could be that the author wants to show Jessie's insecurities. For example, if the fanfiction has James being praised for his skills or looks, Jessie, who is often portrayed as competitive, might feel jealous because she wants that kind of recognition too. Also, it could be related to her possessive nature over James as a partner in their Team Rocket adventures.
One possible storyline could be that Jessie and James, after years of being Team Rocket members, decide to leave that life behind. They realize their love for each other while on a Pokemon adventure. In the fanfiction, they might start a new life in a peaceful Pokemon - filled region, perhaps opening a Pokemon - themed cafe. Their Pokemon would also be part of their new life, with Meowth helping out in the cafe.
Some fanfics that are worth reading are those that explore their backstories in relation to their love. For example, 'Jessie's Heart, James' Soul' which goes back to their childhoods and how certain events led to their growing affection. It's really interesting to see how the author weaves in their past experiences to build a more complex and believable love story between them. Another is 'Love on the Run' which has them running from Team Rocket to be together, with lots of action and romance combined.