Remus doesn't really remember how this sort of, I don't know, relationship started with Severus Snape. Maybe it was Slughorn insisting that his star pupil teach Remus a thing or two about potions, since Potter was such a bad influence on his academics, or perhaps it was the note Remus had accidentally passed to Severus during divination. It could have very well been a combination of both now that he thinks about it.
The Gryffindor and Slytherin had been paired up in Potions for a few weeks now and, despite Snape hating Lupin and his kind for obvious reasons, he found Remus to be remotely bearable. Well, at least more bearable than Potter, Black, and Pettigrew, because unlike them Lupin seemed to portray remorse for their actions as well as his own, or lack thereof. Remus may not have participated in most of Severus' torment, but he was responsible by proxy since he didn't do anything to stop his friends.
But despite all this, Severus was able to turn the other cheek, at least during Potions for the most part. Severus took his grades seriously and he wasn't about to let some grudge distract him because of it. After all that is said and done, Severus was grateful, to say the least, that Slughorn paired him with Lupin and not one of the others. That doesn't mean he liked Remus though! Or that he could learn to like him in time. He was still the enemy.
Remus, however, found it as a great opportunity to get under Snape's skin and ultimately change his mind about him. The Gryffindor kept it mostly professional, strictly about the potions they had to brew, but every so often Remus would sneak in a question or two about Severus' life. Nothing too personal, just simple little things that seemed insignificant at the time.
Like what he liked about potions, what class he liked most, what books was he currently reading, and what his favorite color was (the last one being dumb on Remus' part since it was painfully self explanatory). Once their Potions class was over they would part ways and not socialize with each other outside of class or in any other class. The only exception were projects they had to work on extensively for Potions and that rarely ever happened.
Still, even though they barely talked about anything other than potions, Remus learned a lot from Snape as well as a lot of stuff abouthim and Remus cherished these moments. Lupin never really took the time to admire what a beautiful human being Snape really was underneath all of his snark and standoffish demeanor. Then again, Remus and his friends never made things easy.
One day, however, in Divination, another class the two shared with each other, Trelawney had been giving a lecture on the different types of mediums in the wizarding world and Remus had found himself bored to tears. He usually didn't mind Trelawney's class, found it quite interesting on occasion actually, but he couldn't find the energy to care much for it today.
Remus had his arms folded on top of the table he shared with a Ravenclaw, whose name he couldn't remember, and nestled his chin on them as he sunk further down in his chair, looking like a sad puppy that just got scolded for tearing up the sofa. He tuned out what Trelawney was currently talking about and spared a look around the room to see if Sirius was just as bored, and to say he was would be an understatement. Sirius was nearly pulling his hair out.
Remus decided he shouldn't suffer in silence alone and proceeded to scribble down a note for his friend. He promptly folded it into a little paper airplane and fished out his wand as stealthily as possible without Trelawney noticing. Once the professor had her back turned Remus muttered Wingardium Leviosa and sent the paper plane soaring through the air over to Sirius' table.
He had to concentrate to keep it steady and just as it was about to reach Sirius, Trelawney decided to turn back around at that moment, causing Remus to break his concentration. He quickly slid his wand up his robe sleeve and snapped his attention over to Trelawney for a brief second before looking to see where his note had flown off to. It stayed suspended in the air for a second before taking a nosedive right into a neighboring table.
Severus had been scribbling something down on a piece of parchment when Remus' paper plane collided into his quill. Snape paused, clearly disturbed from his musings, and peered up from behind his dark hair. He scanned the room before his gaze came to rest on Remus who was still looking at him with wide eyes. Their eyes connected and Remus quickly faced the front of the class once again, but it was too late. Severus now knew who the note came from and he'd be opening it any moment now out of morbid curiosity.
Lupin snuck a glance over at Severus to see that the pale boy had picked up the folded piece of parchment and started to open it. Remus didn't know why it made him nervous. It's not like he wrote anything bad or drew anything offensive. Maybe he was afraid Severus would rat him out and get him in trouble for passing notes. It would serve him right for all the times his friends tormented Severus.
Severus unfolded the paper plane with deft fingers, talking his time to carefully open it in case Lupin had thought it would be funny to send him a howler to get him in trouble. He scooted back in his chair a little and finished opening it in his lap so as not to attract any unwanted attention. Thankfully, it wasn't a howler. He looked down at the scrap and read the words scribbled on it.
I am so bloody bored. I wish we could get out of here.
Snape furrowed his eyebrows, wondering what Lupin could possibly mean by them getting out of here. He didn't want to admit it, but the first thing that came to mind made him blush a little. Severus crinkled the note between his hands to hide it and peered over at Remus who suspiciously looked away immediately. Severus couldn't help but let one corner of his mouth quirk up a fraction of a centimeter.
He peaked at Remus from behind his hair, making sure to hold the Gryffindor's gaze long enough to give him a knowing look. Remus watched as Severus turned back to his parchment, tearing off a piece. Severus' quill moved to the motion of his scribbling as he wrote down his response to Lupin. He folded his note much in the same way Remus did and pulled out his wand to send the note sailing over to the other boy.
It floated a bit more gracefully onto Remus' table and the boy snatched it up quickly before his table mate or anyone else could notice. Thankfully, they were both seated in the back so not many people were paying attention to the notes whizzing above them. Remus opened it on his lap to conceal it better and read what Severus had to say.
I know. Anywhere would be better than here right now.
Remus smiled a little to himself because he was surprised that Severus would respond and with such a neutral reply. The first note may not have been meant for Snape, but the one that followed after was for Severus' eyes only. Remus figured talking to Severus was better than talking to no one at all. Not that he minded passing notes with Snape. He just wasn't sure what to say.
The next note took a little bit longer for Remus to send over, causing Severus to glance over at him a few times before Lupin summoned the courage to say something back.
Too bad we aren't in Potions right now. That is loads more fun.
Severus smiled, actually smiled at something Remus had said. Or written, rather. It happened for the briefest second before it reverted into Snape's usual stoic expression, but Remus saw it. Severus almost immediately sent another note back.
You think Potions is fun?
It was hard for Lupin to tell whether Snape was offended by his light hearted take on something he found serious or if he was genuinely curious. Either way Remus replied with what came to mind first.
You make it fun.
He doesn't know where that came from, but he scribbled it down on instinct and sent it over to Severus who opened it up. Lupin watched anxiously as Severus mouthed the words to himself, noticing the faint smirk that graced his lips briefly. Snape tilted his head and wrote his reply with pursed lips and sent it Lupin, eagerly awaiting his response.
You're not a complete imbecile yourself.
It made Remus grin and chuckle under his breath, giving him that faint sense of giddiness he usually got from flirting. The Ravenclaw sitting next to him gave Remus a funny look, wondering what had the Gryffindor amused. Lupin blushed a little, looking away from his dark haired table mate. Once Remus was sure the Ravenclaw wasn't paying attention he turned back to his parchment.
He smiled as he wrote his reply.
Is that your own funny way of saying you like me?
The Gryffindor couldn't discern the look on the Slytherin's face which, admittedly, made him kind of nervous, but Severus acknowledged it enough to give him a deadpan retort.
Don't let it go to your head.
Remus smirked.
Is that a yes?
He was kind of gambling by subtly flirting with Severus, but at the time it had been a reflex he got from Sirius always teasing the pale boy. He'd be lying if he said a part of him was actually invested in flirting with Severus, however. It took Severus a while to answer, but it eventually comes just moments before the class is dismissed.
Maybe.
His breath caught in his throat and he bit his lip in consideration. He spared a glance over in Severus' direction as the other students started to file out. He can see Snape gathering his things to leave, but before he left he looked at Remus, smirking at him with a knowing expression, teasing Lupin further to go along with his vague note. Still, Remus folded the note up and slid it into his pocket for safekeeping. It wasn't until later when he was changing out of his robes for bed did he remember it.
After that, the note passing started to happen more frequently, becoming a regular thing even when class wasn't boring, and eventually Remus was able to convince Severus into hanging out with him at the library. The Slytherin was understandably cautious of Remus' ulterior motives, but Snape showed up anyway despite his suspicions. The temptation and curiosity got the better of him.
"Severus! So nice of you to show up," Remus rejoiced, making sure to use a hushed tone.
"If you and those no good Gryffindors are up to something, I'd appreciate it if you'd just get it over with," Severus informed in a low monotone voice.
"Hello to you too," Remus chuckled, getting up from his seat and smoothing out his sweater vest as if suddenly self conscious about his appearance. "I was a bit worried you wouldn't come."
Lupin had a big dumb grin on his face, something Snape would have normally despised since it was usually associated with some horrible prank Potter had played on him, but this one was different. This particular dumb grin was actually kind of endearing for lack of a better word. Severus found himself hypnotized by it, but promptly brought his attention back to the situation at hand.
"You're not exactly associated with most upstanding citizens of the wizarding community," Severus reminded, taking a step closer towards Remus. "Excuse me if I'm not bouncing up and down with joy for you wanting to meet me in a secluded area of the library."
"You still showed up," Remus pointed out, mirroring Snape's small baby step. "That means something."
"I suppose it does," Severus concurred with a sigh. "But I wouldn't bother reading too much into it, Gryffindor. This isn't going to be a regular thing."
Remus smirked at the obvious lie Severus was trying to delude himself into believing, closing the gap between the two of them. Something changed in Severus' demeanor as Remus got closer, but he couldn't place what it was exactly. Still, Remus noticed it nonetheless no matter how hard Severus tried to mask it.
"We'll see about that," Remus teased, being just as vague as Severus' note that he carries around with him in his pocket.