A/N: Whew, finally, I'm back! Thank you for the reviews, follows, and favorites that I received. The only reason I probably continued writing despite my hectic life is probably because of those. Anyways... this is my first M-rated fanfiction, which obviously isn't rated for death and killing. As usual, I just wanted to test my creativity. (Featuring Blackinnon because I think that they are a rather nice pair, right next to Jily. XD)

~BRB

P.S- I suggest you read this when you are in at least a semi-private space. Don't say I didn't warn ya. Enjoy! ;)

DISCLAIMER: I'm not JKR so therefore I do NOT own any of these characters, just the ideas of what they might be doing during the Marauder Era, or, in other words, the plot.

Scratch, scratch.

Sirius looked up from his Potions essay that he had barely started on and watched as Marlene crossed out a line in her Ancient Runes homework frustratedly.

They were trying to finish up their homework before break starts with their friends, James and Lily, in the library, but it clearly wasn't working out very well. Their "best mates" were at it with them until about a minute ago, having disappeared behind the bookcases after claiming that they "have to find a book". Sirius internally snorted at the idea, convinced that they are probably snogging in the Restricted Area, considering that they are two of the most cleverest students in Hogwarts, and the way they were looking across the table at each other before. Plus, those two had been grinning their heads off when Marlene waved them off out of amusement.

Oh well, to hell with them. At least they aren't hexing each other at every chance that they could get. He grinned when Marlene rubbed her temples with both hands, watching as she lets out a groan while staring angrily at her parchment. He slid in the chair next to her and leaned against the wall. "Looks like someone is having a hard time in Runes…", Sirius taunted, fending off the glare the blonde sent him.

"Shut up Black", Marlene snapped, facing him and narrowing her eyes in irritance, "My homework is already annoying my arse off without your pathetic help so do me a favor and shut your trap."

Sirius ignored her obvious indication to bug off and flicked his black hair away from his eyes. "Why would you even want to continue Runes when you're having such a hard time about it?"

"That's my business, not yours. Now, bug the fuck off before I make you", Marlene threatened, lifting her head out of her hands and running a hand through her hair, making her look even more pretty, if that is even possible.

Heh, she's still mad ain't she? Runes homework always piss her off. Not that I mind, she's so fucking pretty when she is. I now understand James when he feels the same about Evans. Sirius resisted the urge to lean in and stop her agitation about homework. Come on, self-control, come on, you don't want to be like James right? Having his wicked way with his girlfriend in the middle of work, and in the library no less, even if Evans is far from minding. He swallowed hard before smirking. "Come on Mar… we're at this for about two hours, let's take a break, yeah?" His smirk grew wider as Marlene stopped and turned away from him, but not before Sirius saw her cheeks flush a tad bit pink.

"Not a chance, Black, I really want to finish this goddamned homework before break starts", Marlene mumbled, still with her head turned away.

Sirius scooted his chair closer to her, breathing in her faint scent of flowers and strawberries. "Since when have you been worse than Evans, McKinnon? Even Evans is willing to leave homework for later so she can snog James."

Marlene whipped around and gave Sirius a dirty look, bumping into his knee in the process. "Watch it, you selfish, I-can-do-and-say-anything-I-want berk, don't talk about Lily like that. And, so what if they are snogging, that doesn't mean that we should do the same." She turned back to her parchment on the table and continued writing, ignoring the smirk on Sirius's face.

"Aw, you know I don't mean it like that," he murmured, hand trailing up her thigh. Damn self-control, it can go to hell if I succeed at this.

Sirius heard Marlene suck in her breath as his hands continued their light caress up her bare legs. "What in the name of Merlin are you doing, Black?", she growled in a low voice, glaring menacingly at him, quill poised over the next word she was about to write and splattering ink dots on her parchment.

"Nothing, just doing what James and Lily are doing right now, except just changing the "n" and the "o" to "h" and "a", if you know what I mean", Sirius drawled airily, and at the faint color that bloomed across McKinnon's face as she processed what he said (naturally, it didn't take more than a second), he leaned in and whispered in her ear, gently rubbing circles up her thigh. "Mar…come on, please?"

"Only if hell freezes over. Go finish your essay and leave me alone so I can work on Ancient Runes", Marlene retorted, which would sound more demanding and convincing if her face wasn't a brilliant shade of pink. She attempted to move farther away from Sirius, but noticed that she was caught and between the corner of the wall and the person whom she is trying to get away from. Seeing this, Sirius chuckled, hand disappearing under her skirt. Wanting to show her that he has no intention of stopping, his hand suddenly brushed lightly between her legs, feeling her tense up and her breath hitch a bit. "Just so you know, you prat, we are in the middle of a library and I don't even think you are that bold to do whatever you are doing or trying to do right now."

"We are in a secluded area of the library, meaning that we aren't in plain sight, 'Kinnon", Sirius mumbled, laughing quietly to himself as she bit her lip and refused to look him in the eye. He can tell that her confidence is fading, little by little. He brushed her lightly again and slowly went up her knickers, moaning in her ear at the flimsy material between his calloused fingers. At the slight whimper that escaped Marlene's lips, he dipped under the waistband and slipped a finger inside of her.

Sirius felt a smug grin grow as Marlene instantly leaned against the wall behind her head, dropping the quill in her hand, and his heart skipped a beat as he heard a quiet and poorly stifled moan from her. He bit her ear and dragged his tongue around the spot behind her ear that he knew would drive her crazy. The scent of strawberries and jasmine clouded his mind, making him dizzy with pleasure. His other hand untucked Marlene's shirt determinedly and roamed over the heated skin of her stomach, tracing patterns around her abdomen and around her lower back.

"Mmm...I can't...Homework…Ughnnnnn...Si..ri..us…" Marlene pleaded breathlessly between moans. She ran a shaky hand through her blond hair.

"Your bloody homework can go straight to hell. And besides, you just said earlier that it's not my business to care about you doing that crap. Mar, all I care about right now are the sounds you're making" Sirius growled, fingers moving at a fast pace as she moaned his name. He pulled away from her ear and trialed hot open-mouthed kisses along the skin of her neck, tongue swirling and sucking and taste buds humming with the taste of vanilla and honey. Keeping his hand still furiously working inside of her, he lifted her legs up by his other hand and sat her promptly on his lap so she was facing and straddling him. He pulled his face away from her neck momentarily to gasp for air after a good few minutes.

Taking that as an advantage, Marlene scooted closer and crushed her mouth against his. Sirius groaned as he felt Marlene's fingers tangle in his hair and her tongue begging entry as it flicked over his lips. He opened his mouth, allowing access, and tongues clashed, fighting for dominance. He let Marlene win, because he had wanted to do this all along, starting from the time he realized that he have to spend long boring hours doing useless homework when break is only one day behind and all his essays can sod off until the last minute. He can hardly take it anymore, she was so slow, so teasing, skimming over the contents of his mouth ever so slightly. His heart thundered when he felt her smirk against his mouth as he growled impatiently. When they broke apart for a second of air, Marlene's face was flushed and her blue eyes burned and sparkled with a hint of mischief. "We really shouldn't be doing this here, Sirius", she breathed out with a ragged breath against Sirius's shoulder.

"I don't bloody care, McKinnon, you don't really seem to mind", he said, voice hoarse. Then, realizing that he still hadn't withdrawn his hand, he slipped another shaky finger inside of her, picking up pace with both fingers. Marlene moaned against the crook of his neck, biting on his shoulder as she arched her back and rocked her hips. Sirius can tell that she was almost on the height of release, so he moved faster and firmer, moaning as fingers tugged at his hair.

At that exact moment, footsteps can be heard from a few feet away. They broke apart, reluctantly, silently cursing whomever it was that had interrupted them. Marlene slid off Sirius's lap and stood, adjusting her skirt and attempting to fix her hair, which had been tangled in a few places.

James and Lily appeared from around the corner of the bookcase to Sirius's left. Lily was dragging James behind her by his hand. They both looked disheveled, with messy hair and untucked clothing. Sirius smiled, pretty sure he didn't look any better than them. James's tie and the first few buttons of his shirt was undone. Lily was talking to James with a fake scowl on her face, while James himself was grinning dazedly at her.

Sirius caught Marlene glancing at him and he rolled his eyes at the direction of their mates at her. She smirked and nodded. They both gathered their things and left the library after a hasty "See you guys later" to their mates when they joined them at their table.

A/N: So… what do you guys (and girls) think? Personally, I think it came out weird and rushed. But, first try right? I'll try to write another chapter, in Marlene's perspective, cause this is in Sirius's. Anyways… I'm gonna think of what happens after they left the library and type it up.

Hmm… now that I think about it, this can be attributed to Valentine's Day. Any reviews? :)