TF

For three years, Y/N and Bucky Barnes have been inseparable. Best friends. Mission partners. Professional menaces. Y/N is a powerful pyrokinetic known affectionately as Firefly, while Bucky is the former Winter Soldier who somehow becomes significantly less responsible whenever she’s nearby. Together, they’re one of the Avengers’ most effective combat teams—and the reason Tony keeps updating the Compound’s insurance policy. They share clothes, beds, food, secrets, and absolutely no sense of personal space. They love each other completely. Platonically. Obviously. Then Agent Jack Mercer arrives: blond, charming, annoyingly decent, and immediately interested in Y/N. For the first time, Bucky doesn’t like watching someone flirt with his best friend. He calls it suspicion. Sam calls it jealousy. Natasha calls it inevitable. And Bucky is about to discover that after surviving HYDRA, assassins, aliens, and the end of the world, his greatest challenge might be admitting he has a Firefly problem.