So, this is actually barely even smut, since I just can't even write hardcore smut. I only rated it M because some people want to stay far from any hinting or mention of vague descriptions, so. xD

Ten minutes after Loki walked in on Sif kissing the commoner they'd seen in the feast hall only hours before, the god was raging on about her irresponsible tendencies and her poor judgment.

Thirty minutes after, Sif was growing tired of his complaints, and Loki only made himself angrier with every point he came across.

An hour later, and Sif was joining in, fueling the fire that had begun in his green, enraged eyes, her heart pounding as warm blood rushed through her veins, her cheeks flushed and body heated as she matched his shouts with her own.

"What if someone had caught the two of you?" Loki yelled, gazing pointedly at her from across the small expanse of her room, shadows thrown across his features by the dying fire beside them.

"Your reputation would have been ruined," he continued, impassioned, and she stalked over to the hearth, crossing her arms against her chest as she gazed into the flickering orange flames, which crawled and snapped and crackled to please her watchful eyes.

"My reputation would hardly be sullied if I was caught with a commoner, Loki," she ground out, jaw muscles tensing as she turned back around to glare at him, and his incredulous expression almost made her laugh.

Almost.

He threw up his hands in frustration, pressing the heels of his hands against his closed eyelids as he paced back and forth along the length of the far wall, where the cold crept in from the lack of the fire's attention.

"What if you'd gone too far? What if you'd gotten pregnant?"

He looked up to see the realization that she could have made a mistake dawn on her face, to see that he was right and that she knew it, but her expression was empty, and he frowned at her, drawing his brow together as he took a few steps closer to her. She watched the firelight bathe his ebony hair in gold, eyes searchingly roaming his face for any trace of sincerity, but she found nothing.

"What if you'd gotten pregnant?"

He must have felt that the repetition was needed to make her understand, and yet she remained silent and unblinking, shaking her head at him, the long stretch of hair falling from her strict, high ponytail waving at the back of head, looking like waves of ocean water stained dark with ink crashing upon one another. She raised a brow, and felt her throat sting with pain, the effect of half an hour of shouting and another few minutes spent resting her worn voice.

"That would have destroyed any chance you had at becoming a full-fledged warrior, you know that," he reasoned, and she sighed at him, putting a hand on her hip, fingers pressed against the crimson silk of her evening gown.

"I know very well the risks. That will not stop me from doing as I please. You should do well to remember that," Sif scolded coldly, and he drew back, shaking his head in denial.

"But you're…"

His voice abandoned him, and he stood before her, lips parted and cheeks pale (she realized that they should have looked as warm as her own, but then again, Loki was always cold), his round eyes staring intently into her own. She could almost hear the rest of his sentence, spoken like a prayer, hushed and reserved and blessed, in her thoughts, remembered easily after so long spent in her memory.

But you're mine.

It was true, at least, that they were in a relationship, but it was one that Sif couldn't take seriously, mainly because of the crucial secrecy of it all. Loki wouldn't dare let anyone know that he was involved with the warrior maiden of Asgard, too fearful of the public opinion (which had never, in his entire life, been at all kind to him), and Sif didn't want Thor to know.

Thor, whom she held the utmost respect for.

Thor, whom she loved with a small, scarred piece of her heart-but it was the only real piece that was alive.

That reminded her.

Infidelity.

Loki hated the notion with everything he had, had always seen something so intensely wrong with false loyalty, and so it came as no surprise that his envious heart was racing with the revelation that she, the woman he courted in shadows and lone corners, carried with her both a wandering eye and wandering heart.

It was more of a searching, seeking thing, but she never told him where her desires truly rested. It would only hurt him.

And for all of Loki's nastiness, for all of his trickery and dishonesty and, at times, cruelty, she really did admire him, and was wary of causing him any true pain. There were moments in his life that she'd witnessed, moments that she would never soon forget, moments that she'd seen into those mysterious eyes of his like they were glass. In another of those moments, in the aftermath of her infidelity, he was like a child again, wrapped up in his adolescent anger and indignation, consumed by his feeling, treacherous heart, and she saw it in his gaze.

But then it all went to Hel.

The look shut down, his face going blank as she gazed up at him, and her heartbeat sped up in caution. An emotionless Loki was a hurtful one, and she resisted the urge to take a step back.

"Or would you have enjoyed being the local whore?" Loki hissed, and she took a breath, eyes widening in shock.

The audacity.

Her hand swept swiftly and painfully across his face, smacking smartly against his cheek, his head snapping back as she retracted her arm, hands curling into fists as she watched his surprised expression quickly turn into that of anger, and she would have laughed at the reddened handprint on his cheek, if not for the situation, if not for the light igniting in his eyes, if not for the fear swelling in her chest.

His hand, cold as ice and trembling with rage, came to grip at her shoulder tightly, making her wince in pain, and he shoved her against the mantle behind them, hard brick digging into the exposed skin of her back (she instantly regretted wearing a backless dress), and with his other arm he leaned against the wall, effectively trapping her within the confines of his arm span, and her heart pounded erratically. The heat of the flames was felt against her back, and she squirmed at the sensation, wary of getting burned, but Loki only pressed closer to her, silent but shaking with anger, and when she finally managed to glance into his eyes, past the dancing flames reflected within them, she saw past the front he liked to put up.

Loki was hurt, and she swallowed nervously, realizing that it wasn't the physical pain that ailed him.

Infidelity.

He was so close to her, and yet he'd never felt so far away, so unreachable, so far gone. The fire had heated his body in the span of minutes, and he was pressed to her, warming her skin and heating her face, and she found her heart pounding for a different reason, gazing into his eyes as she tried to read the thoughts there. His grip on her shoulder loosened, but she barely even felt it-she was too captured in his stare.

And then she realized, with a blush crawling to her cheeks and a nervousness invading her limbs. There was, burning and restless and hot beneath his gaze, desire, and she let out a slow, quiet breath.

She thought, surely, that she'd lost her mind.

Craning her neck to accommodate his height, she felt her heart thump wildly against her bones and brought a hand up to place it gently on his shoulder, and he stilled beneath her touch, eyeing her warily as she pushed down against him to match their height, and she crossed the small space between them to press her lips to his in a slow, lingering, near tortuous kiss, and started, because of a fleeting impulse, to pull away, but his arms fell from her sides to wrap around her waist, and she thought for a moment that he'd never touched her in so gentle, in so cherishing a way.

His fingertips, warm now and all too eager, slid, exploring, up her back, and she was suddenly glad, in fact, that she'd chosen a backless dress. She brought a hand up to press against his cheek, fingers idly crawling up and past his hairline to card slowly through his hair, and his hold on her tightened as she deepened the kiss.

Abruptly, he hauled her up by the waist so that she could wrap her legs about his own, and he turned them around as she dug her heels into his lower back absent-mindedly, bringing her arms around to hug tightly to his neck.

Loki knew her room well enough from the many hours he'd spent talking with her within its walls to find her bed with ease, and they collapsed onto its silken covers as she scrambled to undo the irritating strap of his leather vest.

He smiled, wicked and amused, and she laughed as he unbuckled it easily, a mere flick of his fingers. She ran her hands down the soft, patterned sleeves of dark green that felt smooth to the touch, smiling as his own hands slid beneath the hem of her dress and explored the pale skin of her outer thigh, fingers brushing lightly over the jutting bone of her hip before skimming quickly across the flat plain of her stomach, and her breath hitched in her throat as she pulled off his vest.

He removed his arm to let the offensive piece of clothing slide to the floor, and pulled his cotton shirt over his head, letting her hook long fingers around the waist of his trousers to tug them down. Eagerly, she guided him down to capture his lips, running her hands up the muscled skin of his abdomen as his hands made quick work of her dress, pulling it up and over her head with ease.

With his weight bearing down on her, she leaned up to kiss his neck, dragging warm lips down the sensitive skin of his throat, and she felt it bob beneath her mouth, smiling as he lifted her chin with his quickly-chilling fingers to kiss her while his other hand roamed down to hook around her thigh. He pulled her leg up to rest on his hip, and she quickly returned to straddling his waist, laughing as he ducked his head to kiss down the length of her torso, lips ghosting over her collarbone to drag across the skin between her breasts, hot puffs of breath tickling her stomach as he cast his gaze up at her, smirking.

Looking at her, it was the first time he'd seen Sif in such a state of disarray, her hair tumbling down around her shoulders and covering the pillows with thick, dark strands after he unpinned it, her milky skin basking in the glow cast by the dying fire, her grey eyes bright with lust and her chest heaving with her deep, panting breaths.

He ran his palm up her arm and twined his fingers with hers, flattening her palm against the sheets, and she felt the cold silk at her back as she rested against the mattress, eager eyes following his every movement as he positioned himself above her, resting with his forearm against the pillows beside her head.

Her legs tightened around him as he thrust into her, slow and savoring and taunting, and she arched her back as she felt him, closing her eyes in pleasure while ignoring the discomfort. Loki enjoyed discomfort, had always found a certain pleasing effect in it, and so she followed suit, breaking his hold on her hand to reach up and hug him to her, chests pressed together as she bucked her hips against his, and she'd never heard him laugh as he did in that moment, so wild and amused and unburdened.

...

Waking in the fading moonlight, Sif sat up gingerly, wary of waking Loki, who slept directly beside her, laid flat on his back with the covers pulled low around his hips. Her ebony hair fell like a curtain from the side of her head, kissing her bare skin as she leaned on her arm, watching the rise and fall of his chest as he dreamed.

With her fingertip, she traced, feather-light and careful, the exact spots she'd kissed him, running down his jawline to brush slowly over his throat and collarbone, drawing lazy circles across his chest and along his stomach, before her touch tapered off below the sheets, and she smiled, remembering, before sighing softly, the waking sun painting the sky pink as she turned to gaze at it.

The golden hue that lingered beneath the clouds reminded her, distantly, of Thor, and her smile fell. Shame tinted her cheeks rosy, and her pulse fluttered as she gasped softly, realization, at last, dawning on her.

Infidelity.

It was just another habit.

Based on a prompt given over on Tumblr (I broke my 'no smut for prompts' rule, but just this once).

Please R&R! Feedback of any kind is always appreciated! ;)

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