The one where Y/n and Harry are good friends, and he's completely mental about her, unbeknownst to Y/n.
During an off day on tour, they're sat together in Y/n's hotel room, having a deep conversation. They reach the subject of romantic interests, and Harry practically spills his guts about this mystery girl he likes. "She's all I ever think about. I'd give her the world if I could," Harry swoons.
Y/n nods, beaming at her best friend's openness and affection, happy for him and this mystery crush of his, and Harry's heart aches because he doesn't know if Y/n will ever know that she's the one he truly wants.