"Come on." James led a bemused Lily down a darkened corridor and up to a portrait of an empty pitcher. "Aguamenti," he said, tapping the portrait; immediately the pitcher began to fill with water, a couple of flowers blooming from its lid, and the portrait swung away to reveal an empty room with large tanks built into its walls filled with all sorts of strange-looking fish. Grinning at Lily's startled expression, James took her hand and led her inside. The portrait sealed itself shut behind them, leaving their faces illuminated only by the electric blue glow of the fish tanks.
"How on Earth did you find this place?" Lily wondered, gaping around.
"Lots of time wandering around the castle at night," James replied. "I'm pretty sure Peter found this one, actually."
"I'm hoping none of this wandering around has been going on during your Head Boy patrolling duties, Potter."
"Only on the nights you don't join me." Lily's lip quirked up in a reluctant smile. "Anyway, Peter and I promised Sirius and Remus we'd let them have our room tonight, so I had to find somewhere else to be alone with you after the ball."
Lily raised her eyebrows. "Alone with me for what purpose?"
"So I could do this." James lifted Lily into his arms and pressed her back against one of the glowing tanks to kiss her, drinking in the sweetness of her lips and the softness of her skin. His hand reached up to her head and began to tease apart the bun she had spent so long putting together, freeing fiery locks of hair to slip down and graze at her shoulders. Lily gripped him like a vice with her legs while her arms snuck their way beneath his undershirt to find his skin, and she kissed his shoulders, his neck, his face in a way that made James let out intermittent, involuntary moans. His brain had shut off completely; he couldn't believe this was actually happening.
Finally, when he found he could no longer catch his breath, James pulled back from her and fixed her sharply with his gaze. "What?" she asked.
"You never told me your condition," he replied.
"Condition?"
"You said you'd go to the ball with me on one condition, and you never told me what it was."
"Oh, that." Lily ran a hand gently through James's hair. "My sister's just gotten herself engaged, and I'm meant to meet her new fiancé over Easter. I need someone to come with me—I may have lied and told my sister I had a charming, handsome boyfriend back at Hogwarts."
"Hmm. That doesn't necessarily have to be a lie, you know."
"A respectful, studious boyfriend who always follows the rules, and never makes any trouble—"
"Well, now, that's just too much to ask of any man." Lily laughed softly. "But a deal's a deal; I'll go to whatever awkward Muggle meetup you invite me to, and I promise I'll do my best to play nice."
"Good," said Lily, "because I already told Petunia that my charming, handsome boyfriend was named James."
"Oh, you sly little witch." Lily laughed again, and James kissed her again, and the two of them spent the rest of the night hidden away in the fish room, exploring each other's bodies and minds in a way they never had before.
