One possible plot could be that Flash Sentry has always had a secret crush on Twilight Sparkle. After Twilight saves Equestria from a great danger, Flash finally musters the courage to confess his feelings. Twilight, who has also grown to like Flash during their adventures together, reciprocates, and they share a sweet kiss.
You can try searching on fanfiction platforms like Fimfiction or Archive of Our Own. These sites have a large collection of My Little Pony - related fanfics, and there's a good chance you'll find stories about Flash Sentry and Twilight Sparkle kissing there.
Sure. A lot of fanfic writers have been attracted to the Twilight Sparkle and Flash Sentry pairing. These fanfics often delve into the characters' personalities and how they interact. They might show Flash Sentry being protective of Twilight Sparkle or Twilight Sparkle helping Flash Sentry with his studies. You should start by searching for the tags related to them on the fanfic websites.
The theme of magic also plays a big role. Given Twilight's strong connection to magic, fanfictions may show Flash Sentry being in awe of her magic or even having some sort of magical encounter himself because of her. Also, the theme of growth, both personal and in their relationship, is quite common. They start from being acquaintances and grow into a couple or very close friends over the course of the story.
One common theme is the exploration of an unlikely relationship. Since Flash is more of an ordinary pony compared to Twilight's powerful and studious nature, fanfics often focus on how they bridge that gap.
One great aspect of Flash Sentry and Twilight Sparkle human fanfiction is the exploration of their relationship in a human context. It allows for new dynamics and character development. For example, in some fanfictions, Flash might be a popular jock in high school while Twilight is the nerdy but brilliant girl. Their interactions can range from initial misunderstandings to a deep connection as they discover each other's true selves.
Often, these fanfictions highlight the contrast between Twilight's intellectual and magical side and Flash Sentry's more physical and practical side. This contrast creates interesting interactions and relationship building.
One popular storyline could be Flash Sentry helping Twilight Sparkle adjust to some new situation in Equestria. For example, when a new magical threat emerges, Flash Sentry, with his courage and Twilight's vast magical knowledge, they team up to face it. Another could be a story about their friendship developing over time. Flash Sentry might initially be in awe of Twilight's magic, and as they spend more time together, they learn more about each other's strengths and weaknesses.
Another possibility is that the fanfic is set in a time of crisis. Flash Sentry and Twilight Sparkle are called upon to use their unique skills to save Equestria from a powerful enemy. Along the way, they face challenges that test their friendship and loyalty, and in the end, they emerge victorious and with a stronger bond.
They might interact with Pinkie Pie in a really fun way. Pinkie Pie could throw a party for them when they achieve something great in the story, like saving the town from a flood. Flash Sentry would be a bit awkward at the party at first, while Twilight Sparkle would be more used to Pinkie's antics. Another character they could interact with is Spike. Spike could be jealous of Flash Sentry at first if there's a romantic angle between Flash and Twilight, but then they end up becoming friends.