After the kiss, their relationship could become more open and affectionate. They might start holding hands more often and being more protective of each other in battles. For example, Gajeel could be more vigilant about Levy's safety, always making sure she's not in harm's way.
One popular storyline could be a situation where Gajeel and Levy are on a dangerous mission together. In the heat of the moment, to comfort each other or as a sign of their growing closeness, they share a kiss. Maybe they are facing a powerful enemy and think they might not make it out alive, so they finally admit their feelings through that kiss.
The 'first time' in 'gajeel and levy first time fanfiction' might refer to their first mission together. In this fanfiction, it could detail how they worked together for the first time. They might have had to overcome differences in their personalities and fighting styles. For example, Gajeel's more brute - force approach and Levy's more strategic and intellectual way. Through this first mission, they could start to understand and respect each other more.
One common theme is the development of their relationship. It could start from a rocky beginning, as Gajeel was not always friendly in the original series, and then gradually turn into a friendship or more. Another theme is adventure. They might go on quests together within the Fairy Tail universe.
Perhaps a fanfiction where Gajeel is cursed with a blue mark that slowly drains his energy. Levy, being the studious mage she is, devotes all her time to finding a cure. Along the way, they have to face many enemies who are after Gajeel's power. Their love and friendship are put to the test as they struggle to break the curse.
One common theme is the couple's anticipation. They're often shown eagerly waiting for the baby's arrival, like in many fanfics where Levy is constantly reading pregnancy books and Gajeel is trying to build things for the baby.
There might be emotional challenges too. Levy could be worried about how motherhood will change her life and if she'll be a good mother. Gajeel may also struggle with his own insecurities about being a father.
Another plotline could be their first fight as a couple. They might have a disagreement over something important, like a decision in a guild matter. Gajeel might be more impulsive and want to take immediate action, while Levy thinks it through more carefully. This could lead to a heated argument, but in the end, they learn to communicate better and resolve their differences.
The popularity of Gajeel and Levy fanfiction, especially the 'lemon' ones, might be due to their contrasting personalities. Gajeel is tough and rough - edged while Levy is gentle and bookish. The idea of them coming together in a romantic and sometimes more intimate way (in the case of 'lemon' fics) is appealing to many fans.