A/N: I imagine this taking place in their fourth year, right as Gryffindor is gearing up for the last game of the year (which, obviously, is going to determine who's going to when the Cup). Anyway, the idea amused me. Le sigh. I wish that JKR would write Marauder Era books too.
"UGH!" Lily stormed out of the library. She could not be more pissed at him. She threw her transfiguration book against the corridor wall, barely noting the contingent of third years who were watching her little tantrum. She whipped out her wand and hissed, "Accio!" as she stomped down the hall, causing her book to fly after her.
Bursting out the castle doors, Lily's fiery hair was ablaze in the afternoon sun as she made her way across the grounds. Once again brandishing her wand, she spat out another spell, Sonorus!
"Sirius Black, if you are still on that godforsaken broom by the time I reach the quidditch pitch…"
"…I'll hex you into oblivion!"
Everyone on the Gryffindor quidditch team winced then flew into a huddle.
"Can't you control that girl of yours, mate?" Sirius directed at James.
"Can it!" barked Riley Thompson. "But seriously, Black, we don't have time for this. What'd you do to her now?"
"I mean it, Black! You are in colossal trouble!"
Sirius grimaced as Lily's verbal tirade got louder, which meant she was getting closer.
"We're supposed to be working on some project together, and this is the fifth time I've had to cancel," Black admitted. "But! This time I actually told her first! I didn't think she'd pull a McGonagall!"
"…that when you wake up, your robes will be out of style!"
Thompson groaned and hit his head on the quaffle, closing his eyes like he had a migraine. "Why do I have the feeling that this is going to be worse than when McGonagall came after you?"
Lily's yelling muffled. The seeker, Maggie Grendal, flew up, looked around, and called out, "She just went into the locker room!"
The team landed, and Sirius positioned himself behind everyone as Lily burst onto the pitch, wildly waiving a scrap of parchment.
"How dare you? 'Sorry, love, but quidditch comes first?'" The team slide out of her way, leaving Sirius exposed. Lily stomped up to him and poked him in the chest with her finger. The team slunk away towards the locker room, except James and Riley, who muttered Quietus! But that did not do a thing to stop her.
"I hate to break it to you, mister, but quidditch is going to have to wait!" Sirius took a step back, but Lily closed the distance. "I have waited and waited around on you to get this stupid project done and there is no way I'm letting you weasel out of it to make me do all the work! You are getting the hell out of that stupid uniform and coming to the library with me RIGHT NOW!"
She crossed her arms and stood there breathing heavily, waiting for Sirius to respond.
He glanced at Thompson, who gave an exasperated sigh, sagged his shoulders, and said, "Practice is over." Thompson then turned and walked off, muttering to himself.
Sirius turned back to Lily, which he instantly regretted, because, as she'd just gotten her way, she was looking haughtily superior. He risked a quick look at James, who gave him a conspiratorial wink and mouthed, "Do it!" Sirius grinned in return.
Focusing again on Lily, he said, "I'll meet you in the library in fifteen minutes!" With that, he reached out and clasped Lily's shoulders. Quick as a flash, he pulled her into him and kissed her firmly on the mouth.
Enraged, Lily pushed away from him and sputtered, "You! …you! UGH!" and smacked him right across the face. She spun on her heel and marched back towards the locker room, while Sirius and James howled with laughter. At the door, Lily turned and shouted, "If you're not in the library in ten minutes, you will regret it!"