There might be some fanfictions that depict Natsu and Lucy sleeping together in a non - inappropriate way, like they could be sharing a room during a quest out of necessity and just sleeping in separate beds or something similar. But it can be hard to find ones that are completely pure in the vast world of fanfiction.
There are likely some fanfictions that depict Natsu and Lucy in a non - adult way sharing a sleeping scenario. Some might focus on their friendship and the comfort they find in each other's presence during a difficult situation like being in a dangerous place and having to stay close for warmth or safety at night. It could be a sweet and innocent portrayal of their bond.
It could be about them having to take shelter during a storm and sleeping in the same small space, like a cave. But they respect each other's boundaries and just have a friendly conversation before falling asleep.
Another plotline could be that they are attending a guild - sponsored camping trip. Their tent gets damaged in a small storm, so they have to share a different, smaller tent. They start off a bit awkward but then end up sharing stories of their childhoods and how they came to be in the guild. As the night goes on, they gradually fall asleep, with a new - found closeness in their friendship.
As they travel, their bond deepens. They start to rely on each other more. Natsu becomes more protective of Lucy, and Lucy begins to understand Natsu's impulsive nature better.
One great Natsu, Erza and Lucy fanfiction is 'The Grand Adventure'. It has an exciting plot where they go on a quest together. The character interactions are really well - written, especially the banter between Natsu and Lucy.
In a fanfiction scenario, they could be at the lemon - scented hot spring alone, and Natsu discovers that the hot spring has some sort of magical property that makes him more in touch with his emotions. He then starts to confess to Lucy how much he values her as a teammate and friend, but in a more heartfelt way than usual. Lucy is touched and they have a really sweet moment together.
I'm not sure specifically as I haven't read this particular fanfiction. But generally, it might involve Natsu and Lucy having some sort of adventure or interaction at a lemon spa. Maybe they go there to relax after a tough mission and something unexpected occurs during their time at the spa.
In this fanfiction scenario, Natsu and Lucy might have a relaxing time in the lemon - scented hot spring. They could start with some light banter, Natsu being his usual energetic self while Lucy is a bit more reserved at first. Maybe they share stories about their recent quests and gradually grow closer in this serene setting.
Lucy and Natsu are the stars of this fanfiction. Lucy is known for her intelligence and her collection of celestial keys. Natsu, on the other hand, is a hot - headed and powerful dragon slayer. Their relationship, whether it's a friendship or something more in the fanfiction, is what drives the stories forward.