Y/n has been friends with Steve and Bucky since the ‘40s. Y/n and Bucky were both secretly in love with each other. An accident happens, Bucky “dies”, and Steve and Y/n ends up in the ice. 70 years later they are found. Steve joins The Avengers and Y/n goes back to singing like she did in the ‘40s at the Stork Club. One day, she invites Steve to hear her sing. Unbeknownst to them, Bucky/The Winter Soldier is there. Y/n is his mission, but he recognizes the song. (It’s “It’s my party/Pity Party”)