Sometimes the jealousy is sparked by misunderstandings. For instance, Marinette might be seen talking secretly with a boy (maybe she's discussing a surprise for Adrien), but Adrien misinterprets it as her having a romantic interest in the other boy. This then causes his jealousy to flare up and often leads to some drama and relationship development in the fanfiction.
One common plotline is when Marinette is paired up with another boy for a school project or event. Adrien then starts to feel jealous because he realizes he has feelings for Marinette. For example, if Marinette has to work closely with Luka on a music project, Adrien might see them getting along well and become envious.
One common scenario is Adrien seeing Marinette and Luka on a date. He might feel a pang of jealousy and then try to interfere in a clumsy way. Another is when Luka gives Marinette a special gift, like a song he wrote for her, and Adrien gets jealous because he wishes he could do something that unique for Marinette.
Some fanfictions may revolve around their secret identities and how they manage to keep it from each other even after getting married. This creates a lot of tension and mystery in the story, and usually ends with a big revelation and a strengthening of their relationship as they learn to trust each other completely.
In many such fanfictions, Adrien's jealousy can be a driving force for character development. It might lead to him realizing his true feelings for Marinette. For example, he could start to notice how much he cares when he sees Marinette and Luka having a great time together. This jealousy can create interesting scenarios like Adrien trying to be closer to Marinette or even getting a bit possessive in an endearing way.
One common theme is Adrien's internal struggle. He's often conflicted about his growing obsession with Marinette while also trying to maintain his normal life and friendships. For example, he might feel guilty for spending so much time thinking about her instead of focusing on his studies or superhero duties.
Well, after the kiss, they could go through a phase of denial. Adrien might think it was just a momentary lapse due to jealousy, and Marinette could be too scared to admit her true feelings. But as time passes, they keep having these small moments where they're drawn to each other. Eventually, a series of events, like a near - akumatization situation where they save each other, makes them realize that they can't keep denying their feelings. So, they start to tentatively explore a romantic relationship.
You can try fanfiction websites like Archive of Our Own (AO3). There are a large number of 'Adrien jealous of Marinette' fanfictions on it. Just search for the relevant tags and you'll be presented with a variety of stories.
Protection is another theme. His possessiveness is sometimes rooted in his desire to protect Marinette from harm, whether it's physical harm or emotional harm from people who might not have her best interests at heart.
One common theme is domestic bliss. They are often shown enjoying simple things like cooking together or having movie nights at home.
Another theme is self - discovery. As they figure out their own feelings, they also discover more about themselves. For example, Marinette might realize how her shy nature has both held her back and also made her more endearing to Adrien. And Adrien may discover that his public persona as a model is different from who he really is inside, and Marinette helps him with that self - discovery. This all ties into their earned desire as they become more confident in themselves and more desirous of each other.
There are also fanfictions with the 'first date' plot. Writers often explore how their first date would be. Would it be super romantic? Or would there be some comical mishaps along the way? It's a cute and popular plot that shows their relationship starting to develop in a more romantic way.