"This has to stop," Sirius said once Lily was out of earshot.
James watched her disappear out of sight, then frowned. "What has to stop?"
Sirius rolled his eyes. "The longing glances, the giggling and blushing and hands touching as you pass the pumpkin juice. She just touched your arm five bloody times during a 30 second conversation about Charms homework."
James touched the sleeve of his jumper where her hand had been and smiled. "So?"
"I can't stand the sexual tension. Snog her or ask her out or something, or I'm going to lock you in a fucking room together until you shag each other."
James brushed off Sirius's comment, assuming he was joking. He should have known better.
A week later, James and Lily took their books to the dormitory to escape the noisy common room. They sprawled out on James's bed, bumping arms when they turned a page or shifted position. James absorbed nothing from the Transfiguration chapter and would have to stay up late to re-read it, but that was a small price to pay to have Lily Evans in his bed, leaving her floral scent on his duvet and resting her elbows on his pillow.
When they both reluctantly closed their books and stood to leave, the door wouldn't budge. James pulled harder, then tried Alohomora, but this elicited only a muffled laugh from the other side of the door.
"He wasn't joking," James muttered.
"What?"
James shook his head. "Sirius thinks he's hilarious, that's all. I suppose we'll have to wait until he decides to let us out – I don't fancy breaking down the door, and I can't think of any other way."
This wasn't true – he could Summon his broom and fly them out through the window, but he didn't want to squander precious time alone with Lily. Instead, they settled back on the bed and played a game of Exploding Snap until Sirius grudgingly opened the door.
That was only the beginning. The next night, Sirius locked them in a broom cupboard during evening patrols. Another time, he and Mary sealed the two of them in the Head Boy and Girl office and stood outside making increasingly filthy suggestions of how they could spend their time. Once, they were trapped in Hagrid's hut for almost an hour while Sirius, Mary, Peter, and Remus peered through the windows and made kissy faces. Lily and James complained and rolled their eyes, but James didn't mind in the slightest, and he suspected Lily didn't, either, except for the time they were locked in the Charms classroom.
"Flitwick was in there with us!" Lily exclaimed afterwards. "How do you expect us to shag if Flitwick is there?"
Sirius shrugged. "We thought he'd already left. That would be a wild threesome, though."
James and Lily both dissolved into helpless giggles, and they let the matter drop for the time being.
Once they started dating, Sirius stopped barricading them in secluded places – they did that on their own. James forgot all about the whole business until months later, when he stepped into a library study room and found Lily seated at the table. Seeing her sent a jolt of apprehension through him rather than the usual rush of joy; she had refused to speak to him since their heated row that morning.
"What are you doing here?" she snapped. "I'm meant to be meeting Remus."
"So am I," James said, heaving a sigh as realization dawned on him. "Hang on." He crossed to the door, but as he expected, it was locked. "Padfoot's done it again."
Lily scowled. "Great. Bloody great."
James sat down beside her and shrugged. "Could be worse. At least Flitwick isn't here for round two of our freaky threesome."
A smile tugged at the corners of her lips. "Flitwick's old news. I'd rather mix it up – what about Sprout? She could tie you up with Devil's Snare, spank you with Venomous Tentacula…"
James smirked. "I didn't know you were into that sort of thing."
She glanced sideways at him, her reluctant smile growing. "I'm not. I don't think Herbology belongs in the bedroom, actually – I'm just angry at you."
"I know." He reached over and took her hand. She didn't pull away, and this gave him a sliver of hope. "I'm so sorry, Evs. I'm an idiot."
"Yes you are." She stared at him for a moment, and then he saw her resolve crumbling as tears filled her eyes. "I'm sorry, too. I hate fighting with you." She wrapped her arms around him and clung to him, hot tears splashing onto his shoulder. He thought he heard the lock click open, but he didn't point it out, because Lily was now issuing a nonverbal apology, and his lips were occupied. Carefully, he slid his wand out of his pocket and locked the door again – he didn't want Flitwick, or Sprout, or anyone else to interrupt – and continued demonstrating to Lily just how sorry he was.