Author's Notes: Written for lunarocks14's "Song and Pairing" challenge.

Pairing: Lily/Sirius

Song: Impossible (Shontelle)

Lily/Sirius is actually a pairing I rather like, but I've never written before. Enjoy.

)O(

"Lily?"

Lily Evans, soon to be Lily Potter, turned around.

She was a vision in her ice-white wedding gown, deep red hair tumbling freely over her shoulders, and green, almond-shaped eyes glittering with happiness. But as soon as she saw who was at her door, her eyes clouded.

"What is it, Sirius?"

Sirius Black stepped into the room and shut the door behind him. There were circles under his eyes, and a worry line creased his forehead. The corners of his mouth were turned down, as if he was in pain.

"I wanted to see you before the wedding," he told her.

"Why?" Lily turned back to her mirror, under the pretense of adjusting her veil, so she didn't have to look him in the eye.

"I wanted to see you one last time before you got married."

"Why?" Lily sounded angry now, and Sirius could see her scowling into the mirror.

Sirius sighed, fiddled with a loose thread on the sleeve of his dress robes.

"I've missed you…"

"You missed me?" Lily turned back on him, pure fury now etched on her pretty, round face. "If you missed me, you might have taken the initiative to see me just once in four bloody years!"

"It's not as if I were trying to avoid you, Lily!"

"Like Hell you weren't." Lily advanced. "Not once, in four years, did you ever bother to talk to me, to explain why you were suddenly all for me and James going out together!"

Sirius looked down at his hands. "I'm sorry, Lily…"

"That's not good enough!" She could have hit him, but restrained herself, balling her hands into fists. "What happened? One day you were telling me you loved me, and the next, you couldn't even bring yourself to look at me!"

There was a pause while Sirius chewed on his lips, and Lily glared at him.

"Is it because I'm a Mudblood?" Lily asked, biting off the words and spitting them out. "You made such a show of not caring about blood–"

"It wasn't that!"

"Well, what then?"

Sirius sat down in a hard, wooden chair, and stared helplessly at Lily.

"I… didn't know what to do," he said, rather lamely.

"What?"

"I mean," he amended, "I didn't know what to do… because I thought I was in love with you."

Lily picked up a bottle of perfume from her table and hurled it at him.

"You thought you were in love with me?" she shrieked. "You didn't know what to do because you thought you were in love with me? For God's sake, what sort of idiot are you, Sirius?"

"I was just being cautious," he muttered.

"Is that something your family taught you?" Lily screamed, practically hysterical. "Did they tell you to take caution when it came to love? What the Hell were you thinking, Sirius?"

"It was… a mistake," Sirius admitted.

Lily grabbed her hairbrush and threw it. Sirius ducked, and it smashed into the wall behind him.

"You bloody well better believe it was a mistake!" she yelled. "And how is it that you only think to remember to explain that when I'm about half an hour away from marrying your best friend?"

"I was… trying to forget…"

"Well, I was trying to forget you too, you know," Lily snarled. "I thought if I just got together with James, I'd fall out of love faster. And look what happened." She raised her arms, indicating herself, in her wedding dress.

"But Lily," said Sirius hurriedly, standing up and approaching her. "I've finally worked it out. I'm not worried anymore. I don't want you and James to get married. I love you, Lily."

Lily glared at him. "It's a little late for that."

"There's still time." He kissed her hard, and then pulled back, with that hopeful-puppy look in his eyes. "You and James aren't married yet. Go find him, tell him you can't go through with it."

"I can't do that." Lily shook her head. "I can't just leave him standing at the alter."

"Why not?" Sirius kissed her again. "People do it all the time. Run away with me, Lily."

"Doesn't it bother you that you're willing to betray your best friend?" asked Lily. "How do I know you wouldn't do the same thing to me if I did run away with you? If you can betray James, why should I think you wouldn't betray me just as easily?"

"I wouldn't!"

She shook her head, and pushed him away.

"There's nothing you can say," she said. "Now get out of my room, and go downstairs, and act like a proper best man."

)O(

Fin