In many fanfictions, their first kiss is often a moment full of pent - up emotions. It might happen during a time of great stress or relief. For example, after Tony survives a dangerous mission, Pepper is so overjoyed and relieved that she can't hold back her feelings any longer. Their eyes meet, and there's a brief moment of hesitation before their lips touch, a gentle and passionate kiss that marks a new level of closeness in their relationship.
One of the main emotions is passion. Fanfictions often depict their relationship as very intense. So when they kiss for the first time, it's a moment of pure passion. But there's also a touch of vulnerability. They are both exposing their true feelings, and that can be scary. Tony, who is usually so confident, might be a bit hesitant, and Pepper, who has to deal with Tony's complex life, is taking a risk by showing her love so openly.
The first Iron Man comic was 'Tales of Suspense #39'. This comic laid the foundation for Iron Man's popularity and his subsequent appearances in various comic series and story arcs.
The moment when Tony surprises Pepper with a kiss after a successful business deal in the fanfiction can be really great. It shows his spontaneous side and how he can balance his business life with his relationship. It's a simple yet sweet moment.
One common theme is the resolution of their differences. Since they had major conflicts in the movies, fanfic might use a kiss as a way to show them making up. Another theme could be the exploration of a hidden or suppressed love. Maybe in the story, they realize they have deeper feelings for each other that they've been ignoring.