Niall:
Niall sang Tal Bachman's 'High Above Me' to you when he asked you out. Even though he's been your best friend for a long time, he had always loved you; but somehow he couldn't believe that anything should happen between you two. When he asked you out, he got a pleasant surprise to learn that you loved him all the same.
Liam:
Liam sang Passengers 'Let Her Go'. When you both broke up, he didn't realize how much he loved you until he let you go. So there he was, staring at the ceiling in the dark, with the same old empty feeling in his heart. He needed you back, and he wasn't about to let you go again.
Harry:
Harry had sung Emblem 3's song 'Chloe' to you at your wedding ceremony. He knew how insecure you were about your body, and how much you wanted to be like your sister. He knew your sister turned everyone on, but you were the only one he wanted.
Zayn:
Zayn had sung Justin Bieber's and Chris Brown's song, 'Next 2 You.' You had thought that he wouldn't stay with you or care for you because he was famous, but that wasn't true. He told you that everything he had is yours. That you would never go cold or hungry. He said that he would be there when you were insecure, and let you know that he was always loving you.
Louis:
Louis sang Vita Chambers 'Fix You'. Louis found you broken beyond repair, and knew that he wanted to be the one to fix you. You wouldn't let him in due to past horrible relationships, but that didn't stop him. Louis couldn't stop how he was feeling; it was like he needed you. And when you would let him, he would fix you.