Collab fic done by me and Leah (borqui_l) from AO3! Please enjoy! Kink Me Merlin prompt: "Arthur/Merlin, Mpreg. Arthur and Merlin have sex while Merlin is very pregnant with Arthur's child (or twins) and Arthur can't keep his hands off Merlin's large belly. Bonus points for Arthur worrying about hurting Merlin at first."

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Merlin aimlessly wandered Arthur's chambers.

He couldn't stop thinking about what the druid seer showed him. Merlin had to prevent it somehow. He and Arthur were supposed to bring on the golden age of Albion. Arthur couldn't die. He had to keep Mordred away at all costs. Merlin glanced over at Arthur eating his dinner, to find him staring intently.

"What's the matter, Merlin?"

When he got no response, Arthur gestured to the chair across him.

"Sit," he said. "What's bothering you? You've been quiet ever since we got back."

Merlin sat down. He looked up and blurted, "I can't lose you, Arthur."

Arthur, surprised, said, "What do you mean? I don't plan to be going anywhere soon."

Merlin was on the verge of tears. He couldn't listen to Arthur saying those things when he saw the prophecy earlier.

"I just can't lose you," he whispered.

"I love you." "Merlin," Arthur said. He walked over to Merlin and cupped his face with his hands. "I love you too, so much. I promise I will never leave you."

"Don't make promises you can't keep," Merlin replied, watching Arthur's expression. "I can't lose you," he pleaded softly.

Any response that Arthur might have had was never heard because Merlin started kissing Arthur. He responded just as enthusiastically. Arthur gripped Merlin's waist and Merlin's arms went around Arthur's shoulders. Neither of them could get enough of the other.

Their tongues slide against each other's. At first, it was sloppy, with entirely too much teeth, but evened out as they discovered what the other liked. Arthur put Merlin on the table, and Merlin opened his legs so they could be closer. He threaded his hands through Arthur's soft hair, and Arthur rubbed his hands up and down Merlin's back.

"God, Merlin," Arthur breathed. "I've wanted this for so long. I want…"

"What do you want, Arthur?" he asked. "Anything you want."

Arthur palmed him, and Merlin practically fell backward with ecstasy. When he was upright once more, Arthur started laughing.

"What?" Merlin asked indignantly, wanting to return the the task at hand. Arthur reached out and pulled something wet out of Merlin's hair.

"You have stew in your hair," he said, still laughing fondly. Merlin joined in, unable to resist the ridiculousness of the moment. He looked back at Arthur, whose hair was a bit tousled and lips raw and swollen from kissing, and looking absolutely brilliant while he was standing there laughing. Merlin couldn't resist.

He put his hand on the back of Arthur's neck and went back to kissing him. Merlin shrugged off his brown jacket and proceed to take off Arthur's blue shirt.

"So beautiful," he murmured, running his hands over Arthur's well-defined chest. He ran his hands over Arthur's scars from past battles. Many were fully healed and were thin, pale marks, but the newest ones still looked a little raw and were raised. Merlin pressed a trail of kisses down the newest of the scars.

"Off," Arthur grunted, removing Merlin's scarf. Merlin deftly took off his shirt and Arthur locked on to his neck, sucking so hard it was bound to leave a mark, running his hands up and down Merlin's sides. "Mine," Arthur breathed.

"Yes, yes, yours," Merlin panted. He pulled back a little and looked into Arthur's eyes to see his pupils blown wide. "Bed. Now." Merlin said.

Arthur picked up Merlin wrapping his legs around Arthur's waist. As he was carrying Merlin to the bed, Arthur started to vigorously suck a mark on Merlin's earlobe. He only stopped his assault on the earlobe when they reached the bed. Arthur put Merlin on down first, and soon followed him, sucking another mark right under his chin.

Merlin flipped them over and made quick work of his and Arthur's trousers. With a wolfish grin, he started to plant kisses all over Arthur's chest, pausing on his nipples, because a bite would look so good right there. When Merlin's teeth closed around the nipple, Arthur let out a loud moan.

"Fuck, Merlin!"

"That's the general idea," Merlin replied, his voice breathy. "Please tell me you have oil."

Arthur reached into the drawers next to his bed while Merlin continued to kiss and bite his chest. He brought out the oil but Merlin took it out of his hands and uncapped it.

"I'll be needing that," he smiled, pouring it on his fingers.

"You're gonna go so deep inside me, Arthur," Merlin said while slowly working himself open. "I'm gonna make you come so hard."

"Fuck, Merlin," Arthur said, cock twitching. "Need to be inside you."

"Patience, love," Merlin replied, now slicking Arthur's cock with oil. He slowly lowered himself onto Arthur until fully seated, Arthur's name leaving his lips.

"Merlin, you need to fucking move," Arthur breathed. He tried moving his hips, but Merlin placed his hands on Arthur's hips, stilling him. Merlin started to move at a slow pace, taking Arthur in deep each time. He relished the feeling of Arthur's cock inside of him. Merlin leaned down and kissed Arthur with as much force and passion as he could. Merlin bit his collarbone and went right back to his tediously slow pace.

"Faster, faster, need to come inside you," Arthur panted and he grabbed Merlin's cock.

That shattered any control that Merlin had. He started going faster, almost bouncing on Arthur's cock.

"Come for me, Arthur," Merlin panted. "Fill me up, wanna be filled with your come."

"Merlin!" Arthur sighed at his release into his lover. Not long after, Merlin came as well, shouting for Arthur, the dim lights of the candles flickering. He collapsed onto Arthur's chest as they relaxed into the afterglow of their orgasms.

He pulled Arthur close as they lay together, legs entangled. Merlin breathed in the scent of Arthur, sweat, and sex. If he smelled like this forever, he would be happy. Merlin snuggled closer to Arthur, who leaned back into the embrace. After what seemed like an eternity, Merlin made a move to leave, but Arthur held onto him tight, and Merlin spent the night with his lover, vowing that he would protect this man until his last breath.

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Arthur and Merlin maintained a steady relationship in the months. But it was evenings like this that Merlin really couldn't stand the prat.

Merlin had been sick all week, not being able to stop vomiting. Arthur had actually been very supportive, bringing him water and rubbing his back and whispering comforting words. But tonight there was a banquet for some important lord. Or was it a knighting ceremony? Merlin wasn't really sure. Arthur had made him come and work tonight despite his vomiting earlier.

Sure, he was feeling a bit better but Merlin really wanted to be anywhere but here. As he stood on the side of the room, waiting for Arthur to need him to fill his goblet or some other task, Merlin couldn't help but think that the only thing in the room with more misfortune than him was the silverware. They just keep being put in people's mouths and stabbed in food. And the goblets as well, never being left alone for more than a minute or two.

As he was contemplating the sad fate of the dinnerware, he heard a small scream come from the high table.

Merlin saw Arthur looking at his fork with a horrified expression. The whole room had gone silent at the scream. Arthur eyed his fork suspiciously and raised it once more, only to be greeted with another, louder scream.

"Dammit!" Arthur swore, trying once more to eat his food, but his fork released the loudest, unfortunate scream yet.

The room went dead silent, only to be filled with the screams of the king's fork. Merlin looked around nervously. He couldn't have done that, could he? Yes, he had been thinking of the predicament of forks, but surely he didn't set the racket off. But deep down, Merlin realized it had to be him; he was the only one with magic. He didn't know how he did it though. As he was trying to figure out what he did, Merlin heard a voice singing loudly in the otherwise silent room.

People started looking around, looking for the voice, when many others began to join in. But not a single person in the room was singing.

It turned out that all of the goblets in the room had come to life and started singing. Arthur looked over to Merlin, who was standing in shock, because he didn't do this, at least he didn't mean to. Merlin had to figure out what was going on. He set down the pitcher he was holding and ran to Gaius's chambers.

All the torches he passed flickered dangerously. He banged into Gaius's chambers to see him concentrated on making some sort of potion.

Gaius looked up. "What is it, my boy?" he asked.

"My magic," Merlin blurted, noting that the walls were changing colors rapidly. "I can't control it!" Gaius pursed his lips.

"I'm not sure if I can help you," he admitted. "But if you go to the druids, they may be able to found out what this is."

"Thank you, Gaius," Merlin said and fled the castle to find the druids.

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He reached the druid camp by the morning. It was just as he remembered it.

Men, women, and children in cloaks, talking, milling around, helping each other. There were many tents and fires that housed many others who Merlin couldn't see. As he walked into the camp, he heard many greetings and wonderings if it was really Emrys in their camp. All the voices subsided when Iseldir approached him.

"Emrys," he greeted, bowing his head. "To what do we owe this honor?"

"I need help," Merlin replied. "Something is going on with my magic, I can't control it."

"Come," Iseldir said, and began walking towards the edge of the camp. Merlin followed him to an open space, wondering what was going to happen. He just needed to get his magic under control. Iseldir sat, and motioned for Merlin to sit across from him. When he did, Iseldir took Merlin's hands in his own.

"Clear your mind, Emrys," Iseldir said serenely. "Let your power flow and focus on the power of the elements around you. Feel the freedom of the air, and the firmness of the ground. Let yourself draw from the nature around you, and let it become part of you."

Merlin followed the odd directions, and felt for the first time in awhile, perfectly okay. He felt weightless, almost without a body. Then he felt a heat begin to grow and shrink in his abdomen. "Open your eyes," Iseldir finally said, and Merlin did. "Well, Emrys, it seems as though you are with child. Congratulations!"

"I… What?!" Merlin said, almost speechless. "But I'm a man. With all the parts."

"Yes, you are most definitely a man," Iseldir replied calmly. "But warlocks are fertile and can be with child. In fact, you are with twins."

"Twins…" Merlin repeated, shocked. "But my magic…"

"Your magic is reacting to the pregnancy," Iseldir explained. "You just need to be more conscientious of what's around you. Reverse what you have done. Nothing severe should happen. I can give you a potion to lessen the effects, but they won't completely go away. Otherwise the pregnancy should be very similar to one of a woman."

"Thank you," Merlin said, amazed. "For everything."

Iseldir once again bowed his head, and the two of them made their way back to the camp. Iseldir gave him the potion and Merlin started on his way back to Camelot. He had to think of a way to tell Arthur.

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Even with time passing, there still was a part of him that didn't believe.

Merlin glanced down at himself, smoothing his palms over his newly hemmed tunic. (Arthur had insisted on him ridding the "tatters" of his wardrobe, meaning nearly everything Merlin owned. He refused to yield about his scarves. Several of those came from Ealdor with him.)

He could no longer see his feet due to the massive size of his belly. And no one commented on it. They all had too much sense to consider that.

Merlin's hands traced slow and with purpose over its firm, round shape.

Twins.

The woman Gaius recommended him assured that his new-found soreness across his abdomen as well as the growing, dark stretchmarks were normal. With Merlin being at six months, and considering it was more than one babe, everything was "perfectly alright, dear boy".

Arthur took the news... as well to be expected. He had eventually warmed up to the idea of Merlin's sorcery, and somehow warlocks being fertile creatures wasn't that great of a stretch. Or at least Merlin assumed this when he told Arthur one evening, seeing no revulsion or alarm in his expression—only confused thoughtfulness.

Merlin winced, sucking in a breath through his teeth loudly as he felt a particularly hard kick inside him. It echoed a weaker response, another flutter of a kick but nothing against his poor organs thankfully.

"Fighting already?" he murmured, beginning to frown, cupping himself gently. "Well, you lot better get it out of your systems now."

He heard the bedchamber door open and didn't bother looking up. Or getting up. Arthur's fur-cushioned chair helped his aching muscles. And it irritated Arthur to see that Merlin set a claim on his favorite seat. Really, Merlin couldn't find a single downside to this arrangement.

"Enjoy training?" he asked, conversationally. "Must be nice to be able run around and bang other people's skulls into the ground."

Arthur grunted, placing down his blunted sword. He raked his eyes over Merlin, when the other man finally met Arthur's critical, mild stare.

"...Have you been laying about all day?"

A flare of anger coursed through Merlin. His magic reflected the emotion, sharply edging his irises with a deep gold, glowing colour.

"Not much else to do," Merlin snapped, gripping onto the armrests. He did feel a bit restless. Standing and walking could possibly fend it off.

He pushed up with some difficulty, groaning aloud.

Within seconds, Arthur appeared at his side, an arm wrapping steady around Merlin.

"Take it easy," Arthur chastised, shooting Merlin a worried look.

Merlin laughed.

"What was that then with laying about?"

The corners of Arthur's mouth quirked up. "Shut up, Merlin," he whispered, pressing a dry kiss against Merlin's temple.

Merlin hummed back, interlacing their fingers as Arthur guided them away from the chair.

"Don't think I will, prat."

"You never do," Arthur said with an extraordinary amount of patience. He led Merlin to the four-poster bed, helping him sit against the mounds of goose-feather pillows. When he picked up Merlin's legs, adjusting them comfortably onto the bed, Merlin remained still but hitched an eyebrow.

"I can do it myself, y'know," he announced, voice bordering on deadpan. Merlin rested one of Arthur's hands over his large belly, enjoying the sensation of warm fingers caressing. "I'm not completely useless." He watched Arthur's nose wrinkle contemplatively.

"Am I mistaken or have you been gaining more weight?"

The blue of Merlin's eyes faded into hot, molten gold.

"You ASS!" he yelled, swatting off the hand and furious at the amusement in Arthur's widening smirk. It didn't last.

Instead of a higher pitched laugh escaping Arthur, he gave a bray.

Merlin blinked.

And then he laughed, tears gathering and slipping down Merlin's cheeks as Arthur with horrid donkey ears turned a funny reddening color.

"HEEEEEEEEEEEEWWWW!"

"Oh, oh," Merlin hiccuped, clapping his mouth with both hands, features smiling so hard they crinkled when Arthur made a confused animal noise, gray-furred ears twitching visibly. "ImsorryArthur—"

Arthur howled—well, he brayed more loudly—in a show of indignation, stomping his foot to further emphasis his displeasure.

"Give me a moment, I'll think of something—"

"EEEEEEEEEEHAAAAWWWWW!"

"Well, you shouldn't have been such a..." Merlin trailed off, lips pressing together at the scathing look. This shouldn't be so hilarious, but it was.

"HAAAAAAAAAWW!"

"No, I don't want the father of my children to be a donkey-man. Shh."

Arthur pouted, crossing his arms grumpily. Merlin shut his eyes to concentrate, mumbling what he hoped was the reversal incarnation.

When he opened his eyes, Arthur's donkey ears were nowhere to be found. Relief flooded him quickly. No, Merlin really had not fancied the idea of Arthur permanently braying every time they wanted to have it off. Let alone how they would explain it to their soon-to-be-born children.

"Not even a thank you?" Merlin asked, snickering as the other man gestured roughly with his forefinger at Merlin and thundered away.

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Arthur eventually forgave him. He always forgave Merlin.

It especially helped when Merlin, naked as sin, dropped to his knees in front of him. Both men were meant to draw up the legal documents to Merlin's consort status, but distractions and hormones arose.

He ripped apart the lacing to Arthur's breeches, nosing against his smalls and breathing in the scent of him before tugging them away.

"Merlin, god have mercy," Arthur gasped out. He shakily reached back for his desk, using both hands to keep himself upright. Merlin's lips went for Arthur's bollocks first, suckling and mouthing them lightly.

At the keening noise above, Merlin clutched at Arthur's hips. His own prick strained aching against the curve of his belly.

He licked the tip of the darkly flushed cockhead, holding Arthur's prick up one-handed as Merlin slide it into his throat. Arthur's fingers crawled into black curls. The pregnant man gladly let Arthur decide the pace, loosening his jaw when the veined cock began wetly thrusting.

Merlin exhaled through his nostrils, shoulders relaxed, feeling weightless as Arthur bobbed his head forward. Merlin's arms touched over the smoothness of his belly, pale hands circling. He savored the feeling, before Merlin lifted his hands and cradled his swollen breasts. They appeared shortly after Arthur got him with child; his nipples once tiny and pink, barely sensitive, now huge and dark and unbearably inflamed.

Rolling his fingers against them, squeezing, he could feel a little of the warm milk inside him dribble from his teats. Merlin knew Arthur loved the view of the new breasts, eyeing them wildly bounce when Arthur could manage to fuck Merlin on his back, ignoring the soft complaints.

Merlin's head pulled back with the aid of the fingers winding in his hair. Arthur's mouth descended on him, exchanging heat and sweet kisses.

"Don't get up," he murmured. Merlin nodded in curious silence, wiping the layer of drool off his chin with a swipe of the back of his hand.

Arthur returned from across the room with loads of furs and blankets.

"Right here?" Merlin asked, grinning. Not that he entirely minded having a round of vigorous sex on their floor, but also couldn't resist a good teasing and letting his king believe he was giving him a hard time. If the eyeroll indicated anything.

"Just roll over, Merlin," he muttered, annoyed.

Arthur threw off his nightshirt and uncapped the vial of oil in his hands, waiting for the pregnant warlock to bend forward and rest on his elbows.

"Not even a please roll over, Merlin." He used a faintly sarcastic-mock of Arthur's tone, grinning bigger instead of being offended. "Am I only spreading my legs for you this time, sire? Hm?" Merlin's fingers to one hand reached back, parting his own cleft, rubbing hard at his entrance. "You want my hole opened for you, clenching for your seed?"

He suspected the filthy words did their job as Arthur's inhale trembled.

"You're not some common whore, Merlin."

Merlin gave a one-arm shrug. "But I am your broodmare as it turns out," he said, tossing a easy smile over his shoulder and chuckling at Arthur's outright exasperation. Oiled fingers nudged away Merlin's hand.

"That's ridiculous. You're to be my appointed consort, and nothing less than that." Arthur told him, instructing with palms gently pressing apart the insides of Merlin's thighs, "Now, spread your legs."

Ridiculous indeed. Merlin cut off his laugh into his forearm, muffling it. The laughter dissolved into whimpering moans, as Arthur slicked him up and filled him, curling and stroking his fingers deep inside Merlin.

It wasn't not enough. It wasn't.

"Want you, uuh," Merlin panted, abandoning his meanings to nonsensical, head fuzzing. "Arthur, now, now please."

He could push back his hips slightly, but Arthur stopped him, withdrawing his fingers.

"Making insolent demands of your king, are you," he said, chuckling and sucking a pink-bruising mark just over Merlin's left buttock. "That shouldn't be so attractive. I blame you."

"Fuck, Arthur—"

The sheer heat and girth of the cock entering Merlin hardly pained him. Arthur pulled him back against his chest, gripping onto Merlin's hips.

"Go slow." Puffs of hot air hit Merlin's sweaty neck. "There's no rush."

Merlin groaned, frustrated. "I'm not made of glass!" he insisted, loudly into Arthur's ear. "We've done this a hundred times!"

Arthur shushed him in a low voice, which only prickled the other man, but at the same moment, Merlin could feel himself undulating and sinking to the hilt. He wriggled down in Arthur's lap, moaning at the pressure of Arthur's cock seated fully. Gods, he felt amazing.

Merlin didn't know he was making continuous, pathetic noises, hands fiercely digging into Arthur's skin until their cheeks nuzzled.

"Hush, Merlin, It's alright." Arthur rubbed soothing patterns over Merlin's huge stomach. He grew to love that in time. Merlin loved Arthur touching him, adoring him. And he got the impression Arthur couldn't get enough of Merlin's body like this. Softer, thicker, rounder.

"You're carrying two of my babes. Until they're born, it's safer this way," Arthur held him close, whispering. "I don't want to hurt you."

The startling intensity of affection bloomed in Merlin's chest. "You won't," Merlin whispered back, turning his head and meet paler blue eyes.

No one else in this kingdom, or in this brilliant world, was worth sacrificing everything for. He would die for Arthur again, poisoned or whammied, and as many times as Merlin's heart needed to fail beating.

He licked into Arthur's welcoming mouth, past his teeth and lips, kissing him messily and fisting his hair before gasping out, Arthur's hips rolling underneath him. There was one spot that never ceased to spark hot lights and constellations behind his eyelids. Arthur's cock dragged and pressed repeatedly on it, as he thrust quickly into Merlin.

Just as Merlin fell into a clumsy rhythm, heavy into his embrace, Arthur shifted him up, murmuring encouragements and helping Merlin onto his side to the pile of furs. He lifted Merlin's leg, carefully spearing the glistening, pinkened rim and feeling the way Merlin clenched round him.

"So close, want," a breathy sigh.

"What is it you want, Merlin?" Arthur hesitated mid-thrust.

Merlin bit down his lip.

"On me," he said murmury, witnessing Arthur's pupils go wide.

"Merlin—"

"You know you want to." Merlin grinned, dimples popping. He massaged his hands over his pale, stretched bump, fingering the lump of his navel gently. "Come on, Arthur. Give your release to me."

"Yes," Arthur said, desperately fumbling to pull out and roll Merlin with his heavy, full belly onto his back. "God, I want that. You're perfect."

He moved between the space of Merlin's legs, as the other man parted them to accommodate his size, pulling at his cock and rotating his strokes almost frantically. Merlin felt the damp tip of the cockhead prod him, right before erupting on him and Arthur groaning out his name.

Merlin raked his fingers through Arthur's body-hot seed, swallowing down a mortified giggle and rubbing it glossy over the front of his stomach, up to his small, distended breasts and nipples.

He would smell like Arthur for days now—good. Maybe they could be left uninterrupted to fuck more somewhere in that time-frame.

With a couple jerks of Arthur's hand, Merlin spurted onto himself, crying out and arching, jaw slack and mouth hanging open. His belly covered in warmth and mix of his and Arthur's cooling, sticky come.

"I'm disgusting," Merlin said, whining. "And my back hurts, you prat."

"Oh, I have faith you'll live to tell the tale," Arthur countered, nestling up behind Merlin, tucking his face against the nape of Merlin's neck.

He kicked defiantly at Arthur's feet winding his before relaxing.

Arthur's gleeful and admiring smile, in truth, excused all that.

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As much as Merlin shared the enthusiasm of the Druids—in the handfasting ceremony of Emrys and Arthur Pendragon—he didn't particularly enjoy the gawking looks, even if they were admiring.

He felt especially grateful that Iseldir was presiding over the private ceremony. The other Druids respected his thoughts and his decisions.

With a little royal persuasion, Geoffrey of Monmouth consented to the modified legal documents, agreeing to a future coronation after the birth.

"Pretty soon," Merlin had whispered in Arthur's direction that morning.

Soon would be wonderful. Not just for the coronation of himself and their babes, but for Merlin to finally feel like himself again. The late stages of pregnancy, how dizzy and breathless he got, how restless, were awful.

Merlin's bare feet ached even in the softest patch of grass, toes poking and wiggling against the blades. But he didn't feel like complaining, not with his heart so gladdened and not with Arthur looking so over the moon.

Thirteen colored ribbons bound Merlin's left and Arthur's right hand. In perfect love and in perfect trust, or so the words went.

"Blessed be all who attend this glorious celebration, and blessed be those united in the bonds of love." The Druid chieftain laid Merlin's free hand onto Arthur's, holding them firmly between his own. "The vows you have made today will last for your lifetimes," Iseldir announced, giving them a benevolent smile.

One of the nearby women held up a chalice, stepping forward.

"This water was drawn from one of our most sacred wells," she said, avoiding Merlin's eye bashfully. "To cleanse your bodies and your minds."

Iseldir nodded to her, letting Arthur separate their hands to take it.

"And now you may take a drink from the cup, to symbolize your love."

Merlin wrapped his fingers around the enameled chalice, touching Arthur's fingers as well. "Remind you of anything?" he asked, smiling.

Arthur groaned, realization flitting across his face.

"You being so keen to die for me?" he pointed out.

Merlin chuckled. "It was a sleeping draft, clotpole."

"... We didn't know that at the time."

The solemn tone from Arthur did not go amiss. Merlin shook his head, lips pursed.

"And yet," he said, earnestly. "I believe you still drank it for me."

Their hands grasping to the chalice shifted, as Arthur took a large sip of the water. Merlin's heart skipped a beat in anticipation, paranoia and fear coiling inside him as Arthur's ruddy-colored lips came back moist.

When Arthur did not fall unconscious in the grove, or his color sallowing, Merlin released the breath he did not know he was keeping in.

"I would have done it a hundred times over, Merlin." Arthur nudged the cup to Merlin's lips, staring back in devotion, "Every single time."

He was not crying. Merlin grinned toothy despite himself and wiped under his sniffling nose with a woolen sleeve, face growing hot.

"And you call me an idiot," he muttered, voice breaking.

"I'm the king, Merlin." Arthur cupped the side of Merlin's face with his empty hand, grazing their smiling lips. "You can't talk to me like that."

"Get used to it," Merlin retorted, dropping the chalice (and ignoring the surprised gasp of the Druid woman), raking his fingers into blond hair.

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