Well, perhaps the fanfiction could focus on how their relationship deepens during pregnancy. They might have more tender and emotional moments together. They could also be in a situation where they need to find a balance between their personal lives as expecting parents and their responsibilities in the larger context of their world. For instance, they may have to make difficult decisions about whether to continue with certain dangerous missions or stay back to ensure the safety of their unborn babies.
Perhaps a plotline could center around the Innocence within them reacting to the pregnancy. Maybe Lenalee's Innocence has some sort of special reaction, like providing an extra layer of protection. And Allen could have dreams or visions related to the future of their child, which could lead them on a new quest to understand what it all means in the context of the D.Gray - man world.
One possible plotline could be that they are in a dangerous situation together, and in a moment of relief after surviving, they share a kiss. For example, after fighting a particularly tough Akuma, the adrenaline and the realization that they care deeply for each other leads to that kiss.
Allen in these fanfictions is typically a complex character. He has his own goals related to the Millennium Earl and the Akuma, but his feelings for Lenalee add another layer to his personality. He might be hesitant in expressing his emotions at times. Lenalee, on the other hand, is very empathetic. She is able to sense Allen's pain and tries to ease it. Their relationship in the fanfiction is usually based on mutual understanding and a growing, unspoken love that gives both of them something to fight for.
Lenalee might become more protective and nurturing. Since she has always been strong - willed, pregnancy could bring out her softer side even more. She may start to see the world in a different light, focusing more on creating a safe and loving environment for her child. Allen, on the other hand, could develop a new sense of responsibility. He might be a bit more cautious in his actions as he now has a family to think about.
Fanfiction about Allen and Lenalee being pregnant can be a creative take on the D.Gray - man universe. Some fanfiction writers might explore the medical aspects, like how the pregnancy would affect Lenalee's Innocence. Others might focus on the emotional journey of Allen and Lenalee. They would need to face the challenges not only from the Akuma but also from the fact that they are about to become parents. It could be a story full of love, worry, and hope, which is quite different from the main plot of the original manga.
There is indeed. Some fanfiction might focus on their relationship within the context of the original story's world, while others might take a more creative approach and place them in alternate universes. It really depends on what you're into.
One great allen and lenalee fanfiction is 'The Bond Beyond Duty'. It beautifully explores their relationship as they face various challenges in the D.Gray - Man universe. The story delves deep into their emotional connection and how they support each other during tough times.
In allen and lenalee lemon fanfiction, one common theme could be the deepening of their emotional bond which then leads to more physical expressions of love. Another theme might be the exploration of their individual insecurities and how they overcome them within the relationship. It could also involve the idea of them being in situations where they rely on each other more, both emotionally and physically, which then paves the way for the 'lemon' aspects of the story.
One possible plotline could be Naruto discovers a way to travel to Barry Allen's world. He then tries to learn from Barry about his speed powers and how to use them in his own ninja - fighting style. Another could be that Barry Allen accidentally ends up in the Naruto universe and Naruto becomes his guide, all while being in awe of Barry's abilities.
You can read it on Archive of Our Own. It has a large collection of fanfictions and is a great place to start.