A/N: This is the way I imagine James and Lily started. It's not very creative or romantic, but it's very real. And that's how I think it really happened. It got creative and romantic from here.
James let out a grunt as he felt a sharp jab in his ribcage courtesy of Sirius. "Ow. What was that for?" he spit out, aiming to elbow his friend back. He stopped short, however, as he noticed what Sirius had already seen.
Lily Evans was sitting at a table by herself in the corner of the library. James wouldn't have otherwise noticed her because she was surrounded on three sides by large stacks of books. Of course, some people felt the need to study for their N.E.W.T.'s. Not everyone had the same dumb-luck and natural knack for acing exams that he and Sirius had.
James licked his lips in contemplation of what to do, and for the first time in his life he attempted to smooth his seemingly windblown hair.
"You have to say something to her," Sirius hissed in a whisper, yanking James behind a bookshelf so she wouldn't look up and notice them staring. "For once I don't see Snivillius lurking around, so there's no chance for you to blow it by randomly hexing him. There's a Hogsmeade trip next weekend. Moony, Wormtail, and I can keep ourselves entertained for one afternoon. Go on!" Sirius urged, not allowing James to make any sort of a retort before he was being pushed back into the open with a loud "Oof" of protest.
Lily looked up at the noise and smirked. "James Potter." She said it as though she were answering a question asked by a Professor. "I never thought I'd see you near the library," she added, setting down her quill and folding her hands on top of the book in front of her.
"Yeah… W-well, I just needed to… Just needed to…" He didn't know what to say that wouldn't sound stupid. In truth, he and Sirius had just set off a load of Dungbombs in the Charms corridor and had run into the library for some quiet refuge, but he doubted very much that Lily would accept that as an answer. "N.E.W.T.'s coming up, you know…" he said lamely with a small shrug. From his hiding spot behind the bookshelf, James caught sight of Sirius slapping his palm to his forehead.
Lily knew very well that James Potter hadn't studied a day in his life, but she found his current lack of arrogance to be extremely endearing. "Study with me?" she asked, parting the wall of books directly in front of her so that he could take the seat across the way. He hadn't planned on having to do actual work, but whatever would soften her up.
He sat down gingerly on the seat as though it was going to bite him and then sighed when it didn't. He picked up one of the books from the top of the stack and pretended to rifle through a few pages.
When he got bored after less than a minute, he set the book back down and spat out, "Listen, Evans." He looked up and met her eyes. The way he said her name was the way he always said it in the halls and it didn't feel right. It was harsh and filled with condemnation because it was usually how she spoke to him, too. He softened his voice considerably and said, "Lily… If you're not going to be too busy studying, would you like to—What I mean is—If you'd have some time and you don't have other plans—"
"Just spit it out, Potter." She said it in a harsh tone although there was a playful smile playing at the corners of her mouth. James Potter stuttering; that was one for the record books.
"Will you go to Hogsmeade with me?" He said it very quickly and immediately assumed it to be a mistake by the way her eyebrows raised. Trying to cover it up he rapidly spit out, "I mean you don't have to if you don't want to, but I figured it's the first trip of spring and it'd be nice to—"
"James." She cut him off in much the same tone that she'd used earlier. He stopped his babbling to look into her green eyes again. "I would absolutely love to go to Hogsmeade with you next weekend."
If James Potter, the arrogant toerag who tried to run the school on a daily basis had been nervous enough to stutter his way through such a request, how could she not give him a chance? After all, even with all the times she'd yelled at him for misdeeds in the halls, he still managed to cram her initials onto every spare bit of parchment he could find, even if he didn't think she knew.
James was in a slight amount of shock, but clearly Sirius wasn't by the loud whooping coming from behind the bookshelf, which immediately led to many shushes from every direction. "You would?" James asked in an exaggerated whisper, just to be sure he had heard her correctly.
She nodded with a smirk as she went back to making notes on the parchment in front of her. "Meet me in the common room at nine on Saturday?" she asked without looking up, knowing that he would, even if he was too dumbfounded to form a coherent answer at the present.
"See you—well I guess I'll—I'm just going to—Bye," James sputtered, feeling foolish as he made a beeline for the exit of the library, knowing Sirius would be at his heels in seconds. As soon as he was free from the silence of the library's walls he let out a happy yell and kicked his heels together in mid-air. Lily Evans had finally said yes!