Arthur and Merlin: Volume One,
NB: Sorry for any misquotes from the original script! Season 1, Episode 1. Merlin and Arthur's first meeting.
"...I would never have a friend who's such an ass."
Arthur smirked. "I may be an ass," he said, "but it's prettier than yours."
Merlin took a step back in shock and laughed. "Woah, Woah, Woah, do you not own a mirror?" he laughed, "Or eyes? Come on, can you not see my cheekbones? They're like amazing!"
Arthur smoothed his hair as he spoke."Excuse me, I think you'll find my hair is ten times sexier than your...black mop thing." He waved his arm at Merlin's head, the man's eyes turning into sharp daggers.
"Oh it is on, sister!" Merlin snapped his fingers in Arthur's face and threw off his jacket.
"Dance battle!" Arthur declared. "Knights, assemble!" The Knights came running in to his side, already fully dressed in their pink sparkly latex, Leon leading the charge in fluorescent yellow converse trainers and a bright blue sweatband around his head. Merlin pulled out an oversized baseball hat and hung a huge gold chain around his neck that said, "Gangsta". He called a man over, who started to beatbox, and the battle commenced, Merlin and Arthur squaring each other up as they edged closer.
As Merlin sat in his prison cell about five minutes later, clutching to his right thigh, he remembered the words of a wise old man he'd met a few years ago:
"If you're going to challenge a prince and an army to a dance battle, always remember to stretch first."
Season 1, Episode 10. Merlin and Arthur are in Hunith's hut, preparing to defend Ealdor.
"No not today," Arthur said. "Put on your own."
Merlin was taken aback by Arthur's words, but he put the armour down on the table and proceeded to tighten the strap on his own gauntlet. Out of the corner of his eye, he saw Arthur's hands fly over the various strings and leather pieces, pulling, tightening and tying faster than Merlin even though possible.
He threw his hand down by his side and looked Arthur straight in the eye.
"Okay, what the actual hell?" Merlin screamed through gritted teeth.
Arthur's eyebrows furrowed into a sharp 'v'. "What?" he said. Merlin's blood boiled and he felt his face redden.
"You can do up your armour like lightning, but you've had me do it for you every single day, moaning and hitting me over the head when I do it too slow or make a slight mistake? I mean, come on! Who in their right mind does that?" Merlin screamed.
Arthur gave out a small laugh, tossing Merlin's anger and inner torment aside with a flick of his hair. "I do!" he said, and walked off.
"One day," Merlin vowed, "I am going to kill him. One day..."
Season 3, Episode 8. Arthur is trying to prepare for his quest for the trident of the Fisher King.
"But the perilous lands are... perilous," Merlin said.
Arthur just sighed and facepalmed. "No **** Merlin."
"Hey," Merlin whined, "that wasn't very nice."
"Oh, I'm sorry," Arthur said sarcastically, eyebrows raised almost as high as Gaius' "No faeces, Merlin."
"That's just disgusting."