Loki hated being trapped. He could not tolerate being bound, despised having his movement restricted, hated being unable to free himself and barely able to breathe under the unimaginable weight of Mjolnir pressing downward as it rested on his sternum. He wondered if, given enough time, it would sink all the way through him—it felt so inexorable a pressure. He hated the way he had to suck in small, shallow breaths, for he would have no hope of drawing another to fill his lungs if he were to empty them to shout and yell and scream for Thor to get his ridiculous hammer off his chest right now or he would—
He hated the way his shoulder blades scraped against the rough paving stones of the sparring room as he twisted and struggled, hoping perhaps to tip the accursed thing off in his squirming, but it was too well balanced there, placed by a hand that meant to keep him pinned and helpless, a hand that knew every detail of the mighty hammer and how to wield it. A hand that had carelessly let the handle down to rest below the line of his belt.
He hated to be trapped, held down, unable to wheedle or threaten because his breath came out only as a harsh, strained hiss. He began to grow light-headed, and as his clarity fled so did his calm. He clawed and grappled at the head of the hammer with arms that felt suddenly weaker than he could have imagined, and he cursed in harsh whispers as Mjolnir remained immovable, not shifting so much as an inch. His whole body tensed against the pressure as he struggled, feeling sweat spring up on his skin and fleet down his sides. And he could not ignore the haft of the hammer as it pressed against him. He imagined he could still feel in it the heat of Thor’s hand. He imagined Thor standing over him in casual triumph, lowering the hammer to Loki’s chest to pin him all too easily, then imagined his hand dipping lower…
He hated the feeling of slumbering power within the hammer. To one so attuned to magic as Loki was, having the hammer pressed against his very body was like embracing a bolt of lightning, and he could feel how his heart beat out a frantic tattoo in its tight-compressed prison at the proximity. So much power there was in Mjolnir that it thrummed and tingled against his skin, ran up and down his body in little jolting sparks. Loki clenched his jaw, breath coming clipped and ragged. He hated being trapped, and hated more that Thor had used the hammer to pin him there, and hated most the memory of Thor’s hand caressing the shaft for a moment after he had placed it down onto Loki’s supine body.
Being trapped thus made him feel helpless, and he hated feeling helpless, hated being under another’s control. He had spent so long learning to evade such a fate and doing all he could to make sure no one would ever think him controllable, simply because of the terror that the feeling inspired in him. And now, the energy that coursed along his form from the hammer only served to enhance his panic. He could not keep his body from twitching, trembling, thrashing in his desperation to escape, even knowing that it was hopeless. He could not hold back the soft whimpers that escaped his mouth, could not halt the chaos in his mind, a stream of words he would speak if he could, pleaseThorletmegostopthispleasenoanythingjustletmebrotherpleaseIcannot—
Some part of him realized, distantly, that perhaps half of Asgard would be pleased to see him trapped there like a half-squashed insect and better pleased still if Thor were to leave him until he rotted, unable to free himself or do any mischief. But it was Thor who could do this, and only Thor. Only he could lure Loki in to be captured, only Thor could find a way to make him be still.
Only Thor could trap him like this, only Thor could casually rest Mjolnir on his body, knowing how Loki’s eyes always watched Thor’s hands as he hefted it and watched the motion of his body as he wielded it in battle. Knowing how Loki once exhausted himself to tears trying to lift it. Only Thor could let the handle rest just so without even seeming to try. And only Thor could then walk away behind him where he could not follow with his gaze, presumably leaving Loki there to gasp and struggle and perhaps eventually give in and despair before he would return to remove it. A reminder of Thor’s power. Of Thor’s power over him.
And Thor had done it out of sheer annoyance with him for “not fighting fairly,” though a moment after the accusation Loki had reappeared with his face inches from Thor’s, smirking gleefully as he pointed out that, yes, not fighting fairly was exactly his intention, because a fair fight meant that at least one combatant was a fool who would deserve it when he wound up holding his intestines in with his hands. He did not add that, really, it is Thor who does not fight fair.
His head spun and his insides trembled, and he wondered how long he could last with so little air, with the hammer slowly crushing him. Wondered whether Thor would just leave him like that until he fell unconscious. He was flushed with heat all over from his struggling and he could feel the broad, deep bruise already forming where Mjolnir sunk into his flesh, and the handle was still pressed against him, trailing down from his belly, and he dizzily tilted his head back, trying to discover if Thor had truly left him there or if he had returned yet, perhaps to watch from the shadows. He could not spot him.
Loki hated the feeling of being caught, and hated himself as his head grew more muzzy and his hips began to move minutely of their own accord, pulled into desperation by the feeling of Mjolnir’s haft rubbing against him as he struggled. He couldn’t stand to feel as he felt under the weight of Mjolnir, and he was painfully, impossibly hard, and he could barely breathe, and he wondered if Thor’s hand would be as hot around Loki’s cock as it must have been around the hammer's shaft to leave it so warm. He couldn’t help but think of the hammer as he had seen Thor use it countless times—and the fluid shift of Thor’s muscles as he swung it, the snap of his cape and the flick of bright hair flying out around him, and Thor’s rumbling yells as Mjolnir sang through the air in the midst of battle, coated in a deeper red and dripping with death and power, calling down a lightning that seemed about the shatter the world.
That same power ran like electricity through Loki’s veins, pounded heavily in his chest and in his head and in the pulse-point of his throat, and he scrabbled against the floor with his fingertips, knowing how completely trapped he was, under his brother’s absolute control, and all he could think to wish for was release of another kind, and he realized that he had forgotten not to let all the air rush from his lungs, because when it escaped with a shuddering groan, the pressure on his breastbone suddenly increased, turning from discomfort to pain and he couldn’t breathe couldn’t speak couldn’t even think and some part of his mind wondered if Thor was causing the heady rushes that flowed from the metal of the hammer and coursed through his body, pulling every muscle in him taut as a bowstring, and he made one last, frantic, writhing struggle, and he wondered if Thor knew what this was doing to him and how much he hated this sensation, and he wondered if Thor’s prick would feel as good pressed against his if Thor held him down with his own body, if Thor pinned him and trapped him and took him while he had no chance of flight or resistance, if Thor’s touch would send scalding shivers flying up and down his spine as the pressure of Mjolnir on his body did.
As the world grew grey around the edges, he envisioned again the end of their sparring match, the sight of Thor’s implacable frown as they fought and the feeling of Thor’s hands yanking Loki out of his leap so quickly that he did not feel the impact of his body smacking against the ground even though it knocked his breath away. The sight of Thor reaching for the hammer he had but a moment before set aside, and the moment of confused dread when Loki did not yet know whether his brother meant to strike him with it, or—
Loki hated the feeling of being trapped, of being powerless, and when Thor had bent over him with a flicker of mirth in his eye, he had set Mjolnir softly on Loki’s chest and tipped the handle downward, giving the end of it a gentle pat just before he let it go, as if he were giving Loki a gift. And there was that same look of amusement in Thor’s face when he reappeared—upside down from Loki’s perspective.
“Enjoying yourself, brother?” As he said it he reached out a fond hand to the head of Mjolnir, stroked it with his thumb, sent a renewed jolt of power through Loki’s body.
Lost in a haze of grey mist and the blood-red pounding of his heart in his throat—unable to breathe, unable to speak—Loki’s mouth fell slack in a silent cry as he met his brother’s gaze and came.
He was still reeling from it when the weight was lifted away by Thor’s hand. And finally, at last, he breathed.