Disclaimer: (Ocaso sings) HP's not yours, not mine, not yours, noooot miiine.
Keeping track…
James had always been bad at keeping track of days, but today, as he awoke, he knew it would be the best day ever. The fair mid-spring weather, the beauty of the dawn beyond the windows, the absence of a smothering pillow – sure, Sirius thought it fun to set it on him, but James begged to differ – and the existence of a certain redhead made him fill his lungs with the warm air and proceed to choke from breathing in too hard.
Yet he was used to swift recoveries, being in the Gryffindor quidditch team, so he jumped up from his bed, took his glasses from his nightstand and headed to the bathroom. Just as he got to its door, he did a full turn: Sirius' bed was empty.
Now, in all fairness, everyone deserved to wake up first someday, but Padfoot? James frowned, thinking hard if they had agreed to do something to the Slytherins but nothing came to mind, so he shrugged it off and went on as usual. Thirty minutes later, he emerged – refreshed – to Peter's snores, Remus thrashing in his sleep, and Sirius' empty bed.
Of course, one possibility was that he had finally set his priorities straight and had started looking for a girlfriend of some sort. He was, after all, not ugly – though James would never admit that his friend was handsome – but he seemed oblivious to girls, concentrating only on pranks all year long.
Curiosity getting the best of him, James walked over to his trunk and pulled the Marauder's Map out of the mess. He looked around quietly before saying "I solemnly swear that I'm up to no good" and starting his search of Sirius. Where was he off to, and with whom?
He didn't have to look long and his findings only made his curiosity heighten: what was Sirius doing alone in the Common Room with Lily?
James whispered "Mischief managed" and stepped out of the room, going down the staircase as stealthily as he could. Their voices were too quiet for him to make out what they said, but it didn't seem as if the lovely redhead was about to eat Sirius up and spit him back out, as she usually did when she and James had a row. He frowned again, but it was short lived, as he was suddenly filled with the fear of having been discovered: their words had stopped when he had finally walked into the Common Room.
He scanned the room with his eyes, but didn't see them. Had they walked out without him noticing? But that suspicion was put to ease – or rather, to unease – when he heard a girlish giggle coming from the floor in front of the fireplace…
The numbness that washed over him was soon replaced with murderous horror, but James fought the urge to kill his best friend and decided that Sirius was innocent until proven guilty. Hey, maybe he was telling Lily about a prank that they had both pulled off, making her laugh and fall deeply in love with him! – But that was beside the point and he crawled to the couch to either absolve or convict the young man.
Nothing could have prepared him for the sight before his eyes.
Lily was lying down next to Sirius, who had propped himself on one elbow to look at her. Both their clothes were in disarray and they glowed in a way that sent shivers down his spine. Sure, Sirius was free to like anyone, but he couldn't have – not Lily! Yet it was confirmed to be true when Sirius laughed, caressing Lily's side and kissing her forehead gently, making her giggle all over again.
At this point, James couldn't control himself any longer and he gave up worrying about dementors and Azkaban. However, as fate would have it, just as he was getting ready to pounce, the couple – no, no, the pair of students, a simple pair of students! – started talking again.
"I'm serious, you are great…" – Sirius' husky voice said as he started tracing her face with his hand. – "But what if James finds out?"
"Finds out about what?" – She asked, kissing his palm.
Sirius trembled and pulled his hand away.
"Sorry, Lily, it's just too much." – He said softly, baffling James. After sleeping together, what on Earth could be too much? – "Anyway, what if James finds out about us? He'll kill me…"
"Don't worry," – She replied, her eyes completely mischievous as she took Sirius' hand again. – "I'll make sure he doesn't hurt you. If he loves us both, he won't mind."
Sirius drew in a breath as Lily slowly kissed the inside of his wrist, and he sat up.
"Lily…" – He said warningly, trying to get his arm back from her grasp. – "Lily, if you keep doing this, I'll be in a much more compromising position in a few minutes."
She sat up, too, smiling.
"But you agreed to this in the first place!"
"Sure I did, but I don't want to tarnish James' mind forever, with a vision of you and me sh-shaa-sh – well – you know…"
"I love it when you stutter…" – Lily replied seductively as she leaned closer to him. He arched an eyebrow, clearly giving up his self-control, and pulled her into a close embrace, which surprised her.
"Don't make me say why I love you…" – He retorted, and they both dissolved into laughter and giggles.
And laughter and giggles were too much for James to withstand. He stood up from his hiding spot with his wand in his hand and a hurt look on his face. However, Lily and Sirius continued playing with each other's hair and tickling each other, immersed in a world of their own. He opened his mouth to say something – anything, as long as it was hurtful, colorful and threatening – but Sirius beat him to it.
"Happy April Fool's Day, mate."
And as Lily and Sirius untangled themselves from each other, laughing at James' look of incomprehension and then at how understanding dawned on his face, James' mind was made. In other words, after he beat Sirius to a pulp for giving him the scare of his life, James was determined to buy a calendar: he clearly needed to keep track of days…
Author's Note: Well, I hope you enjoyed this. I got up early today to do my Hotel Accounting homework, but this idea just wouldn't leave me alone! And remember, people: give feedback! Cheers!