One scenario could be that they meet in the attic. Nina is looking for some clues about the house's past, and Fabian is there by accident. They startle each other at first but then realize they both have a thirst for knowledge about the secrets of the house.
A fanfiction could depict that their kiss was part of a dream sequence at first. Nina was dreaming about Fabian and in the dream, they shared a beautiful, passionate kiss. When she woke up, she was confused but also realized her true feelings for him. Later, in real life, the same situation occurred and they actually kissed, making the dream seem like a premonition of their relationship.
They might have a mysterious encounter in the old corridors of the House of Anubis. Maybe they stumble upon a secret room while exploring together and start to piece together more of the house's mysteries.
After the kiss, they might face some challenges from their friends. Some friends could be jealous or think that their relationship will get in the way of their mystery - solving adventures in the House of Anubis.
In many fanfictions, the Nina and Eddie kiss can be seen as a culmination of their character arcs. Eddie might have been secretly longing for Nina for a while, and the kiss is the manifestation of his feelings. Nina, on the other hand, could be realizing her true feelings for Eddie at that moment. This kiss can also be a plot device to drive the story forward, for example, causing jealousy among other characters or leading to new conflicts.
One common theme is probably the reaction of the other characters. They might be shocked, supportive, or even suspicious. Another theme could be how Nina copes with the situation herself, like dealing with morning sickness or her changing body while still being involved in the mysteries of the House of Anubis.
One possible fanfiction could be that Nina and Fabian meet in a mysterious old library. They both reach for the same ancient book at the same time. Their eyes meet, and there's an instant spark. Fabian is initially shy but musters the courage to ask Nina if she'd like to explore the library's hidden chambers together. As they wander through the dusty corridors, they start sharing their dreams and fears, slowly falling in love.
The specialness might also come from the unique personalities of Nina and Eddie in the context of the House of Anubis world. Their different backgrounds and character traits coming together in that one kiss can be really interesting. For example, if Eddie is the more adventurous one and Nina is more cautious, the kiss could be a moment of their two worlds colliding in a beautiful way.
Romance is also very common. Fans love to explore the relationship between Nina and Fabian, from their first awkward meetings to deeper emotional connections. Writers often create scenarios where their love blossoms.
Imagine a scenario where Nina and Fabian are in a theater group. They are both cast in the lead roles of a romantic play. As they rehearse their lines, they start to feel the emotions of their characters bleed into their real lives. The passionate scenes on stage become a catalyst for their own real - life attraction. After the play is over, they continue their relationship, having discovered a deep love for each other through the world of theater.