The unwritten stories Lily tells James in "Gryffindor Colors." Not necessary to read GC to understand.
Sirius glanced at him. "I wouldn't mess with her, Prongs. She's one messed up chick." James shook his head. Just what did Sirius mean? He was James Potter. He didn't have to watch anything. He could mess with anything he bloody wanted.
"I have something for you." He said, staring down at a piece of jewelry in his palm. Lily had to smile; it was plastic with scarlet and gold beads. Lily couldn't help letting out a giggle. "It's Gryffindor colors." He seemed awfully proud of the fact, Lily couldn't help but notice.
"Everything I've ever told you has been a lie! I never meant any of it! Sometimes I wonder why I wanted you so bad." Lily looked at him. "Please, don't do this. When you put this ring on my finger, you promised you wouldn't leave me."
Sirius loved Lily. James loved Lily. Lily didn't know who she loved.