Another possibility is that it could involve a new character created specifically for this fanfiction. This character could be a hybrid of Twilight - like abilities and some form of super - speed, and they could be the one sharing the kiss with either a well - known Twilight character or a Flash character.
One idea could be a crossover of the Twilight universe and the Flash's world where their powers interact in unique ways during the kiss. Maybe the vampire's immortality and the Flash's speed combine to create a sort of time - frozen moment during the kiss.
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.
Barry Allen from The Flash and Rachel Berry from Glee could be main characters. Barry's speed could be used in interesting ways, like helping Rachel get to auditions on time or saving her from some danger in the city. They could form an unlikely friendship and be at the center of the story.
Two young artists could be the main characters. They meet at an art exhibition and are immediately drawn to each other. They start flirting using the phrase 'kiss kiss love you baby'. One is a painter and the other is a sculptor, and their different art forms add an interesting dynamic to their relationship as they support and inspire each other.
It could also feature a princess from another kingdom as the main character. She might be sent to this prince's kingdom for a political alliance, and the 'kiss to my prince' moment could be a turning point in their relationship. Maybe she initially dislikes him but the kiss changes things. There could also be a joker or a court fool as a side character who helps or hinders their relationship in some way.
There could be Peter's best friend. Maybe his friend has been encouraging Peter to stand up to Flash all this time. When Peter finally does it, his friend is right there by his side, supporting him.
Maybe Jacob could be a main character. He could be in Vegas for some reason and cross paths with a Twilight couple on their honeymoon. His presence could add some tension and a different dynamic to the story.
Leah Clearwater could also be a central character. She has her own complex story within the wolfpack. Maybe a visiting werewolf from another pack, who is more open - minded about poly relationships, could come into the story and start a relationship with Leah and some of the male pack members. Another option could be Seth Clearwater, as he is a likable character and could be part of a poly relationship dynamic within the pack.
Well, obviously the princess would be one of the main characters. She could be a strong - willed and kind - hearted princess from a far - off land. As for the Twilight side, a vampire like Edward could be a main character. His brooding nature and special powers would create an interesting dynamic with the princess.
Bella and Edward could be the main characters. Imagine Edward working part - time at the coffee shop to blend in with humans. Bella, a regular customer, is immediately intrigued by his pale complexion and mysterious eyes. They start a relationship that unfolds within the coffee - shop setting, with all the challenges of a human - vampire love story, like Edward's struggle to control his thirst and Bella's acceptance of his nature.