Arthur,” Merlin said softly, tongue thick in his mouth.

“Yeah, Spartacus?”

“I just… I need you to know.”

Arthur swallowed and took a step forward. “Need me to know what?”

“You’re the best part of my day.”

Arthur smiled softly, fondly. “You too, Merlin. You too.”

Merlin slumped back to the pillows, exhausted, hurting, yet happy.

It was careful at first, a soft hesitation; Arthur breathed in against the kiss and let Merlin pursue it. Then Merlin made a soft noise and Arthur found he could not slow for gentleness; he gripped Merlin tight, manhandling him toward the bed and down onto it, kissing him, pushing him back amongst the pillows, the dark reds and worn ivory. It was as though a fire had been lit inside Arthur’s head; he wanted everything at once — the bare column of Merlin’s throat, his capable fingers, his narrow hips, and things Arthur had only imagined.

Merlin was kissing him still with lips barely parted, brief, keen, breathless kisses that made Arthur’s head swim with how much more he could have — he wanted the taste of Merlin, wanted his mouth, his tongue, wanted the texture of every word Merlin had ever spoken to him.

Headcanon AU:
Peter and Edmund decided to travel west of Telmar on one of their exploration trips. They came across a small kingdom with a prat-like prince with a good heart named Arthur and his witty manservant named Merlin. After finding out Merlin had magic, the two kings offered safe haven, if ever needed, in Narnia. Merlin declined, but thanked the Kings nonetheless.