AN: This fic is an AU, Lily/Severus. It should be pretty long. I love feedback.
How had it happened? Lily Potter sat up, shakily, and glanced down at the sleeping figure beside of her. Funny. In all the years of their friendship, she had never seen him sleep before. He looked peaceful, almost childish, his guarded features smoothed out and the slightest of smiles playing on his lips.
She sighed on stood up, looking around the room for her clothes. It was difficult in the half dark, but Lily hoped to get away without waking him up. No such luck. His eyes fluttered open and watched her intently. His face was guarded once again and it somehow made him uglier.
"You're going, aren't you?" he asked. "Back to him." His voice was spiteful, but underneath it, Lily could tell that he was wounded.
She slipped into her skirt. "He's my husband, Sev. You're just … you're just. I don't know what you are." She found her bra and struggled to clasp it in the poor light.
"And I suppose tonight was just you playing with me. Revenge for my becoming a Death Eater?"
"You told me you wanted out!" Lily stood up straight, dropping her blouse. As distressing as it was to think that she cheated on James, it was much more distressing to think that she might have slept with someone who was truly a follower of Voldemort.
"I do," Severus hissed. "More than I want anything. I've asked you to talk to Dumbledore."
"I have. It's just tricky, Sev." Her eyes couldn't meet his. She, the ever-optimistic Gryffindor, had gleefully promised to help when he contacted her two months ago. But it was proving harder than she had thought. There had never been a case of a full-fledged Death Eater switching sides before and Dumbledore was suspicious.
Severus crossed his arms. "What about tonight? Why did you do it?"
Lily stopped buttoning her blouse, and tried to think of the gentlest way she could phrase it. "Sev, you were crying."
"I most certainly was not," he objected immediately.
"There were tears in your eyes. I haven't seen you cry since you were a kid. When you kissed me – I just – I just couldn't stand to reject you. I'm sorry."
Snape looked away. "So it was pity."
Lily frowned. "I guess so."