One idea could be that they go on an adventure together to find a lost magical artifact. Along the way, they discover new things about each other and their relationship deepens.
They could start a guild of their own. In this process, they deal with various difficulties like recruiting members, finding a suitable place for the guild, and all these experiences bring them closer and show their married life in a new light.
One idea could be a time - travel plot where Lucy, Rogue, and Sting are sent back in time to the founding of Fairy Tail. They have to navigate the early days of the guild while also trying to find a way back to their own time. Another could be a magic - swapping scenario, where they accidentally exchange their magical abilities and have to learn to use each other's magic to fight a new, powerful enemy.
Well, a plot could revolve around Sting being overly protective of Lucy during her pregnancy. He might try to keep her from going on any dangerous missions, which could lead to some cute arguments between them. Then there's the idea of them preparing a nursery together. They could have different ideas about how it should look, like Sting wanting it to be all about Sabertooth's colors and Lucy having a more whimsical design in mind. And of course, there could be a plot where they discover that their baby has some special magic abilities even before it's born.
One plot idea could be Sting and Lucy teaming up for a really difficult S - class mission. They start off not getting along well because of their different guilds' rivalries in the past. But as they face various challenges during the mission, like powerful dark mages and dangerous terrains, they gradually come to respect and care for each other. Eventually, they complete the mission successfully and form a strong friendship that could potentially turn into something more.
One idea could be that Sting and Lucy are on a joint mission. They get lost in an ancient, magical forest. As they struggle to find their way out, they start to share their deepest fears and dreams, which brings them closer. Another could be a story where Lucy is in danger and Sting has to fight off a powerful dark guild to save her, and during this, he realizes his true feelings for her.
One plot idea could be that Lucy and Sting discover they are pregnant around the same time. They could then support each other through the various challenges of pregnancy in a magical world. Maybe they have to deal with magical side - effects on their unborn children due to their own powerful magic.
One idea could be that they discover the pregnancy during a mission. They then have to balance their duties as mages with preparing for the new life. Maybe they face some challenges from their guild mates who are initially worried about how it will affect their performance in the guild.
A possible plot could involve a dark magic that starts affecting Fiore. Lucy discovers some ancient texts about it, and she realizes she needs the help of Sting and Rogue. They go on a journey to find the source of this dark magic. Along the way, they encounter many enemies. Sting and Rogue use their Dragon Slayer magic to fight, while Lucy summons her Celestial Spirits. As they get closer to the source, they find out that one of their old enemies has returned and is using this dark magic to seek revenge. Together, they combine their powers to defeat the enemy and save Fiore.
There could be many different fanfictions with Lucy and Sting having a pregnancy plot. However, it really depends on the creativity of the fanfiction writer. Some might write it as a way to develop their relationship further, perhaps adding more drama and complexity to their story.
A plot idea could be that Desmond and Lucy are on a mission to find a hidden Piece of Eden. Along the way, they face many challenges and have to rely on each other's strengths. Maybe Lucy is the one who is more knowledgeable about the historical context and Desmond uses his Eagle Vision to navigate through dangerous areas. They could also face internal conflicts within their own organizations that threaten their mission and their relationship.
One idea could be that Lucy's pregnancy is unexpected and she has to deal with the reactions of her friends and family. Some might be overjoyed while others are worried. Another could be a story where the father of the baby is a mystery and Lucy goes on a journey to find out who it is. Maybe she discovers some secrets about her past relationships along the way.