Crosspost from AO3.
Written to: Shake It Out - Florence and the Machine, Savant - Pirate Bay
"Loki, are you sure this is going to work?" Steve asked, struggling to twist his neck around to see himself in the full length mirror.
Loki snorted. "Of course it'll work. I get that the time you're from frowns upon things like this, but please, don't be such a prude. Besides, my brother is absolutely besotted with you anyway; I'm sure what you wear won't matter to him. And you said you wanted to do something different."
"But it's so tight. Is it supposed to be this tight?" Steve muttered as the steel bones of the velvet corset dug into his ribs.
Loki's face popped up behind his shoulder. "Would you stop complaining? I swear you're worse than the one time I turned Mjolnir into one of those toy hammers that Midgardian male children adore. Of course, Thor didn't complain so much as chase me around, which, by the way, is much less intimidating when he's swinging around something that looks quite a bit like brightly coloured plastic." He grasped the nylon strings and yanked, and Steve felt his breath rush from him, forcing him to gasp lightly at the air.
"Oh please, that's definitely not attractive, gasping like a dying fish," Loki snapped as he tied the strings into a small bow. "Don't be so dramatic. Look, it's finished already."
Steve eyed himself in the mirror. The dark crimson velvet dug at his ribs and compressed his waist into a semblance of female curves. The white lace trimmings stretched tightly across his chest and hips.
"I look like a woman."
Loki rolled his eyes. "Well, obviously. Oh, you can't wear those horrid undergarments with this, you'll ruin the whole thing."
Steve managed not to bat an eye as Loki snapped his fingers and his tighty-whities changed into a pair of black silk panties.
"That's much better," Loki commented as he circled around Steve, examining him critically.
"How am I supposed to take this off?" Steve asked. Loki looked up at him.
"Oh you dear, sweet idiot," he snorted. "The whole point of this is that Thor will take it off for you. Of course you may have to guide him, that blundering buffoon might end up choking you quite a bit along the way." At Steve's worried look, Loki laughed. "Don't worry, I've heard from many Midgardians that it is a highly erotic experience. And I'm certain if you kept on gasping and floundering like a beached whale, my brother would be alerted to whatever was troubling you."
Steve is glad that there aren't any emergencies that day, because he's not sure if he would be able to struggle out of the corset to arrive at the site in an orderly manner. He can feel the steel bones pressing into his skin and forces himself to breathe quietly and calmly.
This plan works very well until dinner.
Loki eyes him across the table, arches a thin black eyebrow with an evil grin. He feels the strings tighten slightly beneath his clothes - oh, the trickster - and he chokes on his mouthful of bread. The food gets stuck in his throat and he coughs loudly, gasping for air, which he can't seem to get enough of.
Thor, who is sitting beside him, claps him heavily on the back to dislodge any extra crumbs. As he pats Steve's back more gently, his fingers run across the steel boning at the top of the corset and linger there. He eyes Steve with a look that Steve doesn't catch, but Loki can see, even from across the table, the slight dilation of his brother's pupils.
Loki excuses himself from the table, a laugh bubbling in his throat as he goes off to find a tiny kitten to dominate the world with.
Thor presses Steve up against the door of their room as soon as he closes it. His broad fingers run across Steve's chest, feeling the ribs of the corset as they compress and loosen with Steve's breaths.
"And what is this?" he muses, pressing kisses along Steve's jaw as his hands work on unbuttoning Steve's shirt. Steve can already feel Thor pressed hot and hard against his hip, and his mouth goes dry.
"I - um - it's a corset," he mumbles, reveling in the feeling of Thor's broad hands resting on the flares of his new waist.
Thor's eyes twinkle with amusement. "Yes, indeed it is." He looks down, admiring the way Steve's chest struggles to lift and draw in air. "It is a very nice one. One of Loki's better ideas, I must say."
"Yes," Steve agrees. "Natasha says he has an eye for fashion."
Thor pushes Steve's shirt off his shoulders, letting it flutter to the ground. His hands run down the front of the corset, and Steve holds his breath as Thor's fingers stop at the button of his jeans.
"And this?" Thor asks, tracing a finger along the slight hem of black silk peeking out above the denim.
"Loki -" Steve gasps; Thor is crowding his space and it is hard to force air into his lungs and try to think clearly with the blood rushing to his crotch - "Loki said it would look better if I wore those."
Thor eyes him with hunger. "The All Father did say Loki was wise beyond his years," he muses as he hurriedly unbuttons, unzips, and rips Steve's jeans off. "Look at you," he breathes as he steps back, and Steve feels very exposed, very hot and rather bothered. "You are a beauty."
Steve feels blood rush to his cheeks. "You don't call men beautiful," he mutters, trying to hide his blush.
"No?" Thor asks, taking his wrist and leading him to the bed. "My words fail me at the present moment. Loki always did warn me about using my entire vocabulary in one encounter."
Oh God, Steve thinks as Thor pounds into him. Oh God. I must remember to thank Loki after this.
Thor is hot and heavy on top of him, and with every inwards thrust he grasps the nylon strings in one hand, and tugs as he strokes Steve's erection through the black panties, which are probably absolutely ruined and Steve will have to apologise to Loki about them but he can't really think about that right now, not when he's trying to get enough air to breathe and scream at the same time.
Steve's breath comes in mangled half-sobs, and his vision sparks white and black with every thrust, every stroke, every tug. The only words that leave his lips are things that sound like "Thor," or "please," and his tears trickle down his face because God, he can't, he definitely can't -
"Would you like to come?" Thor whispers in his ear as he leans over and yanks the corset even tighter around Steve's heaving chest.
"Yes," he sobs, "yes, yes, yes, I want it, I need it, please, I can't -"
Thor bites kisses into the nape of his neck and presses into him roughly. Steve can feel his orgasm approaching in bright sparks, a wire coiled in the pit of his stomach, and he tries to draw in enough air just as Thor grasps the nylon strings firmly and tugs them harshly, so tight so tightly, and Steve peaks with a silent scream and spills white across the inside of his panties.
He wakes up a while later, curled up against Thor's chest. He draws in a deep breath, glad to be able to taste the air again. Thor watches him with a quiet smile.
"That was rather enjoyable, Steven," Thor murmurs as he traces fingers around the ridges of reddened skin where the bones of the corset had dug in.
"Yes," Steve agrees, blushing slightly. "It was...good."
"You look very pretty when you are struggling to breathe and make noise at the same time," Thor says, running soft fingers through Steve's hair.
"I don't look like a beached whale?" Steve asks.
"Pardon?"
"Loki said it might be unattractive."
"Ah yes, well, he is adopted, you know."
Steve laughs.
The next time Loki comes to him with a tiny black kitten cuddled in his cape and looks up at him with pleading green eyes, Steve rolls his eyes, sighs deeply, and says that Loki will be allowed to keep it.