Well, perhaps the baby could be a magical being sent to them for protection. Natsu's brashness and Lucy's nurturing side would both come into play. They'd have to deal with villains who are after the baby. Along the way, they start to see their future together more clearly, like a family, and it deepens their bond not just as friends but as potential partners.
One possible plot could be that Natsu and Lucy accidentally end up taking care of a baby dragon. They struggle at first with things like feeding it and getting it to sleep. But as time goes on, they grow attached and learn a lot about themselves and their relationship in the process.
Well, perhaps in this fanfiction, Natsu calling Lucy 'baby' is a sign of a new level of closeness in their relationship. It could start with Natsu protecting Lucy in a dangerous situation and instinctively calling her 'baby' as he holds her close. This then leads to Lucy being a bit flustered at first but gradually getting used to it and even liking it, and it becomes a special part of their bond.
Well, perhaps the story could start with Lucy finding out she's pregnant. Natsu is initially shocked but then becomes super excited. The pregnancy is filled with little adventures, like Natsu trying to build a perfect nursery using his magic in a rather clumsy way. And when the baby is born, it brings a new sense of hope and family to the whole guild. Everyone pitches in to take care of the baby, and it grows up surrounded by love and magic.
One possible plot could be that Natsu and Lucy go on a really dangerous quest together. During this quest, they face a powerful enemy that separates them from the rest of their guild mates. They have to rely solely on each other for survival. As they struggle through various challenges, they start to realize their true feelings for each other. In a moment of great danger, when it seems all hope is lost, they confess their love and share their first kiss. This could be the start of their relationship in the fanfiction.
One possibility could be that they discover they're having a baby unexpectedly. Natsu might be initially confused but then super excited. Lucy would probably be a bit more practical, thinking about how to raise the baby in the Fairy Tail guild environment. The guild members would be overjoyed and offer all kinds of help, like Happy bringing little gifts for the baby to be.
One idea could be that Natsu and Lucy accidentally end up taking care of a baby dragon. Natsu would be excited to teach it fire - breathing tricks while Lucy would be more focused on keeping it safe and fed. Another plot could involve a magic spell gone wrong that turns them into babies themselves, and they have to figure out how to reverse it while in this state. It could also be a story where they find a lost baby in the forest during one of their quests, and they decide to raise it together, which would show their growth as characters in terms of responsibility.
Growth could also be a theme. Nashi would be growing up, learning about her powers (if she has any), and about the world around her. Natsu and Lucy would also be growing as parents, learning how to take care of a child, make decisions for the family, and balance their previous lives with their new roles as parents.
It could be a dark wizard who wants to use the baby's power for his own evil deeds. Maybe the baby has some special magic that the wizard thinks can help him take over the magical world.
Most likely. When one character calls another 'baby' in a fanfiction, it often implies a certain level of romantic affection. So, it's a good bet that the 'natsu calls lucy baby' fanfiction has romantic themes.
Well, in many such fanfictions, it often involves Natsu and Lucy having a special connection related to dragons. Maybe Natsu's dragon powers play a role in bringing them closer in a romantic or fated - mates - like way. For example, they might go on adventures together where Natsu's dragon instincts protect Lucy in a more profound way than in the original story, and their relationship deepens as they face various challenges side by side.
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.