Merlin peered into his Seer's glass, looking back on his younger self with a fond expression. He chuckled to himself as he mused over the image that he and Arthur used to make, Arthur dressed in the finest cloths that a prince could hope to wear (and looking entirely too good for his own safety), with Merlin chattering away at his side, wearing his usually dopey expression and that ratty neck-scarf that Arthur, in spite of his constant hounding, could never convince Merlin was a completely unnecessary fashion item.
"You may think it's useless, sire, but not everyone is lucky enough to be able to sit on their royal arse and have everyone fetch and carry for them. Some of us actually work up a sweat during the day. So rather than sweat straight through my shirt, because some people actually do their own washing, I wear the scarf. See? Useful."
Arthur had been on about the scarf all afternoon, and every time Merlin looked up, Arthur was staring at his neck. Merlin had thought that his explanation would shut finally Arthur up about the scarf. As he went back to polishing Arthur's sword, still smirking over his small victory, Merlin didn't notice Arthur in front of him until he was being yanked out of the chair by the neck-scarf in question, and hauled up until he was face-to-face with the Prince.
"First off, Merlin, how dare you insinuate that I do nothing all day? Maybe I should dress you in my armour and send you out to face my knights tomorrow morning. Second, if you really want to fuss about someone who does nothing all day, try Morgana. I'm sure she'd love to hear all about how you feel."
Arthur's face was so close to Merlin's that Merlin could feel the tiny puffs of air ghosting over his lips as Arthur spoke. Merlin realized he had been standing there with his mouth open, and he licked his lips to wet them.
Arthur followed the motion with his lips and when he began to speak again, his tone was almost predatory.
"And third, I never said it was completely useless. I just said it was unnecessary as a part of your attire. Oh, it has its uses. Many more than you know."
Merlin, being a bit taller than Arthur, was already off-balance by the Prince's holding on to his scarf, and the tiny jerk that Arthur gave was enough to cause Merlin to tip over, his lips landing unevenly against Arthur's. Merlin didn't even get a chance to think before Arthur's tongue was ghosting across his lips, searching for entry. The feeling of Arthur's hand at his waist caused Merlin to gasp, and granted Arthur to entrance to explore his mouth.
They were kissing, wild and fumbling, because what do expect when it's Merlin and Arthur's hand is still tangled in his scarf? Arthur drew back for a second and Merlin just stared at him, open- mouthed and panting. Arthur's free hand came up to undo the scarf from Merlin's neck, bringing it up to cover Merlin's eyes.
"Arthur, what are you-," Merlin started but whatever protest he had intended to make was cut off by Arthur's lips against his as the Prince finished knotting the scarf behind his head.
Arthur drew back and rested his forehead against Merlin, their breaths mingling in the small space between them. His hands slid down Merlin's back to stop at his waist and Arthur could feel Merlin tense.
"Just let me show you," Arthur whispered to Merlin's lips, as his hands came around to meet at the laces of Merlin's breeches, undoing them quickly.
Merlin could hear his heart pounding in his ears, mingling with this sound of his own ragged breathing, effectively shutting out all sound but that of Arthur's voice, which was forever strong and clear in his head, so when Arthur stepped away and Merlin could no longer feel him or hear him, Merlin panicked.
"I'm right here," Arthur said, stepping close to Merlin again.
Merlin didn't hear Arthur, couldn't hear him over the sound of both their sharp gasps. There was suddenly heat between there, flesh burning against flesh, and Merlin realized that Arthur must have stepped back to untie his own breeches.
The two of them just stood there, breathing hard and leaning against each other. Merlin couldn't see, his sight obscured by the scarf around his eyes, and his other senses were in a frenzy. Blood was rushing in his ears, and he could smell the sweat on Arthur, so close that his mouth swore it could taste the salt on his tongue.
Worst of all, Merlin could feel everything; the pressure of Arthur's forehead against his, the weight of Arthur's hands on his waist, Arthur's warm breath slowly drying out Merlin's lips, and the slow, painful, amazing heat as Arthur started to move against him.
Now that they had started to move, they couldn't stop, and it was a clumsy, awkward rhythm that neither Merlin nor Arthur had the time or the presence of mind to correct. They were moving fast and hard against each other, clinging to each other like two men drowning, just trying to stay upright, to maintain that sweet, hot contact.
Arthur came first, all sharp, jerking motions, and a growl low in his throat, spilling himself all over Merlin. When he reached between them and wrapped his hand around them both, Merlin was crying out before Arthur could fully close his fist, shaking and promptly collapsing, taking the Prince with him.
When Merlin's breathing slowed, Arthur reached over and untied the scarf from his eyes. Merlin looked back at Arthur, their gazes never straying from each other as Arthur reached down to clean them off with that same scarf before throwing it behind him carelessly.
"See? Useful," Arthur said, mirroring Merlin's previous statement, causing Merlin's mouth to break into a dopey grin that threatened to stick that way, before dragging Merlin on top of him for a kiss, the Elder Merlin gazing at them both through the glass, wearing the same expression as his younger self.