Thunder's shaking the shutters of Merlin's tower room, the rain coming down in a thick curtain he can't see the lights of the town through. It's as if his window opens into a lake, a waterfall, and he pulls the shutters closed, latches them tight.

He won't be expected tonight with it storming like that and there's something he wants that he doesn't know how to ask for. If he can begin things, maybe he can guide them in the direction he cannot stop fixating on.

On the way across the courtyard, he soaks up a river's worth of rain. He ducks into an empty chamber, swiping at his eyes, and dries his clothes and boots and hair. When he was a kid, he used to make a dry spot in the storms to walk beneath. He'd stay out in the rain for hours, until the sky hiccoughed and dripped and stilled. But here at the castle, he can't risk the spell.

When he slips the key into Arthur's door, the Prince starts a little on the bed but doesn't wake. His hair-trigger responses to noise never kick in until they've left the citadel, which is both alarming and hysterical, given the history of poisons, potions and thievery in the Pendragon bedchambers.

Giving Merlin a key made sense. Letting him keep it even after Arthur found out about his magic? It was proof beyond Arthur's word that he still trusts Merlin with his life. So naturally he's going to abuse the trust, or take advantage of it, at the least.

Closing the door and latching it again behind him, Merlin pulls off his boots and crosses the room, shedding his servant skin as he goes. Neckerchief, boots, belt. Tunic on the back of a chair, trousers on the foot-board. By the time he reaches the bed, he's on even footing with his prince, who lies sprawled, nude, on his stomach.

No circlets or livery, just tanned, smooth skin and the clean lines of hard-worked muscles.

The covers he'd spent too long pulling the wrinkles from that afternoon have been kicked to the foot of the bed, bunching up below Arthur's long, sprawled legs. He lies face-down, one knee bent and hitched up nearly to his waist so Arthur's backside stretches in a smooth line that blends down into his thigh and continues all the way to the back of his knee.

Wanting him is like aching for knighthood when you're just a peasant with excellent fighting skills, but Merlin's lucky, the luckiest bastard in Camelot and he takes Arthur's ankle, drawing it down the bed, gently urging Arthur's leg straight.

Merlin sinks a knee into the mattress and swings his other up to sit over the backs of Arthur's warm, strong thighs. They flex beneath his groin as Arthur stirs, sending a shiver over Merlin's skin. Merlin leans down on wide-spread palms and Arthur's next breath is gasped as he is pulled abruptly out of his dreams.

Dropping to his stomach, cock pushing with an involuntary jerk of his hips between Arthur's tense arse cheeks, Merlin stretches up and whispers in the prince's ear. "Hello," he breathes, tucking his nose into the curve of Arthur's neck and inhaling the warm, sun-baked sleepy scent of him. "Why don't you just lie there for me?"

"M'waking up. Just give me a second," Arthur murmurs, hips pressing down into the mattress and back, lifting up into Merlin's groin without a single protest.

"No, I…" Merlin begins, rocking his hips in a slow, hard glide, his cock ready. He's been awake for hours, holding off, not touching except to squeeze himself through his trousers hard enough to hurt, hard enough to shock the lust back up into the base of his spine where he can tolerate it, where he can savour it. He's waited all evening for this, for the castle to give up the day and go to sleep and the storm to break and Arthur to wake up beneath him for the first time ever.

"Thought you might not come," Arthur says, pushing back and up against him as he thrusts down and God, yes, it's just like Merlin pictured it would be, Arthur looking back over his shoulder with so much want that Merlin can't breathe. His cock slips down into the space behind Arthur's sac on the next thrust and he groans, rocking his hips.

"Do you want me like this?" Merlin asks, his voice breaking as he pumps his hips forward, his knees open in a vee over Arthur's calves. "Do you want me to…"

He can't say it, can't find the words in his blistered brain.

"Feels good," Arthur tells him, voice gravelly with sleep and desire, "Yeah, but I want to fuck you."

Merlin shivers and nods, thrusts again, his cock thickening to the point of pain as he presses deep into the tight hold of Arthur's thighs. "Wanted to do this for so long," he whispers, hips finding a rhythm and pulling, tugging back and sliding between again and again, harder, pushing Arthur into the mattress.

He wants every inch of himself between Arthur's clasping thighs, curls his hands over Arthur's strong shoulders and uses the leverage to slide harder, faster, push all the way down until all he can feel is damp flesh surrounding his cock and the soft give of the bed beneath Arthur pressing against the head of his cock. He groans and shakes as Arthur digs a hand beneath himself and cups it over the tip of Merlin's cock.

His thumb presses deep into Merlin's slit on the next grinding, growling thrust through Arthur's tight thighs and Merlin breaks apart, moaning louder than the thunder outside, head ducking down between Arthur's shoulder-blades, fingers digging deep into the rope of muscles and hips stuttering, jerking wildly at too much sensation, too much clinging, gripping heat and it's nothing but a relief when Arthur pushes him off and flips onto his back, fingers bruising on Merlin's thigh as he pulls Merlin on top of him, urging him to kneel up with a slick, wet hand between his thighs.

Merlin whines as the fingers smear over his sac, across his hole and press slowly inside, his thighs vibrating as he holds himself up over the slim hips and lets Arthur work him open with Merlin's own slick cum.

The scent of himself on Arthur's fingers is intoxicating, the taste forbidden and heady on his tongue as Arthur's other hand presses to his mouth, palm dragging over his lips as if to stop his breath. It works. Merlin's dizzy in seconds, mouth open and sucking against Arthur's palm, lips moving to suck on his fingers. He gasps at the wide, burning stretch of Arthur's third finger pressing close in against the first two, spearing into him in long, slow, hard glides that make him crazy for the stretch.

"More." It's rough and needy and Merlin shakes his head, not tonight, he won't beg tonight. He grinds his hips down, taking what he wants, reaching between his legs as Arthur's fingers slip out of him, pushing a fourth up to the others and holding them in a tight bundle as he stares, drunk with need, into Arthur's shocked-wide eyes and sinks, grinds, growling down onto all of them. "More," he groans, this time demanding instead of begging, his vision blurring at the pain lacing through his need.

It's hot like fire, the burn of so much, but he wants it, he can do it, his body is made for it, made to take, meant to hold, his arse clenching and his hole aching as he exhales hard. Arthur licks his lips and tears his eyes away from Merlin's and they both look down, Merlin's legs so unsteady that he shakes on the fingers, the movement jerking a gasp from his chest.

"Fuck, Merlin, God. That's – how can you…" Arthur trails off, big, strong hand closing on his wobbling thigh to hold him still. He bites his lips, breathes. Looks up at Merlin again. "Does it feel… do you like it?"

"Yes," he groans and leans into Arthur's strong hold a little, lowers himself another degree, letting his head fall back and moaning as the fingers widen and his arse clenches in response.

"Yeah," Arthur breathes, and his features are absolutely feral as he watches Merlin take more of him than he ever has. "You're so tight, so…"

Merlin smiles a little and lowers himself further, drawing his hand down the center of Arthur's chest. "I want your cock," he whispers, biting his lip as he pushes himself down mercilessly, balancing with a hand on Arthur's sweat-slick chest.

Sinking down, Merlin cries out as the pain bleeds into pleasure and back, Arthur's fingers wide and deep inside him, palm pressed tight between their bodies, thumb pushing into his sac and Merlin's thighs are screaming their thanks as they rest against Arthur's.

Desperate and full but not full like he needs, he rocks up and back on Arthur's hand, groaning as their cocks slide together. "Now, please," he begs, shaking his head at the whine in his voice. He lays a hand on Arthur's wrist, pressing his weight onto it for strength, and Arthur's eyes are on his face again. "I want you. Now."

"Fuck," Arthur hisses. He opens his fingers as he pulls them free, the walls of Merlin's body stretching beyond pleasure, slipping into delicious, permanent pain he'll be able to remember forever because it's nothing like any pain he's ever felt, nothing like ever before. "You – that was so fucking gorgeous.

Merlin bites his lip, pushes his arse up and back, sliding wet and open along Arthur's cock. "I'm not done," he says, his voice just a shade unsteady as he takes Arthur in hand and lines the leaking cock up to his hole. When Arthur looks down, Merlin does, too, memorizing the sight of himself spread wide, thighs trembling, aching, clenching hole twisting closed and shocking open with the hard, smooth thrust of Arthur's cock as it pierces into him.

He cries out, his body clinging to Arthur, and it feels like he's tighter than ever, the way he just pulls Arthur in. He curls down into it, arse clenching tight but he takes all of Arthur, down to the root in one long, fierce movement and he sits, pushes himself as tight as he can and reaches for Arthur's shoulders, dragging him up with fingers clawing at the back of his neck, twisting into his hair.

He holds Arthur to him, in him, as close as they've ever been, as tight as their bodies have ever pressed together, clutching and grasping and rubbing hard over Arthur's skin, mouth finding Arthur's and taking that, too, taking his thrusting tongue and nipping teeth and breath hard against his cheek.

He pulls back, hips grinding down into Arthur's lap, jerking and gasping as the cock inside hits up against the white-hot cluster of nerves that makes his body arch and his toes flex against the soft mattress. Arthur's fingertips rub hard down his spine, his mouth closing on Merlin's throat as his hands cup Merlin's arse, pulling him open, pulling him apart as he moves up into every roll of Merlin's hips. The fingertips curl up inside him along Arthur's thrusting length and it hurts again and Merlin moans his shameful pleasure, his knees slipping impossibly wider on the soft sheets.

"Ride me," Arthur murmurs against his neck, biting and sucking until Merlin tilts his head back to give that up to him, too. "Hard,Merlin," he gasps as Merlin pushes against his chest, pushes him back on the bed.

The fingers slide wetly out of him and up his hips as Arthur falls back, pulling Merlin down over him. His hands are hard and tight on Merlin's arse as Merlin begins to move, finding a steady, inexorable, thudding heartbeat of a rhythm, dragging his body up and back on Arthur's flexing cock. "I want to fuck you," he breathes against Arthur's ear, grinding so hard he can feel Arthur's cock everywhere.

"Oh, fuck," Arthur moans, arching up to take Merlin's mouth and Merlin lets him because he's so far in control that he needs Arthur to take something away.

He clenches his body as tightly as he can and stills until Arthur is shaking, cock jumping against the brand of fire inside Merlin, bumping against it like it's nothing, like it's not going to kill Merlin if he doesn't stop. "God, Merlin, yes." Merlin does it again. Again, his body furling and coiling like a snake ready to strike, a storm ready to break. "God, like that, don't- Don't stop. Just. Fucking, ride my cock, God," Arthur growls, hands bruising-tight on his arse, dragging him up and back, frantic and ragged.

Arthur clenches his teeth and comes, cock pulsing deep inside, the jerking, halting motion against Merlin's screaming bundle of nerves pushing him headlong over the edge and he spills, spurting slick heat all the way to Arthur's collarbone, his head thrown back, then dropping forward, breath sucked in and exhaled shakily out past his smiling, parted lips.

Coming down is like crashing to rocky earth instead of soft mattress and Arthur's insistent, strong arms wrapping around him. He pushes his face into Arthur's shoulder and groans, cries out a little as Arthur's hands gently urge his thigh up and over. He aches, his entire body battered and shaking with the burning of muscles. Arthur reaches down the bed and pulls the duvet up over their sweat-damp bodies, taking Merlin's face in his hands and making Merlin look at him.

"You're unbelievable," he whispers, kissing Merlin's forehead, his eyelids as he lets them fall closed, his lips, gently, sweetly. "Thank you," Arthur murmurs into his mouth as they kiss and Merlin nods sleepily, happily, dropping his head to Arthur's shoulder and curling against him, sinking into the feeling of Arthur surrounding him, listening as the storm slows and calms on the ramparts of the castle.

~ finish

Notes:

For rebeccaann08 who requested Arthur/Merlin, fingering, Merlin bottoming from the top

Herein lie many run-on sentences and a very slutty Merlin. Ye be warn'd.

Quick & dirty beta by _makeachange!