"So," Merlin asked, "Does that mean you're not going to hit me anymore?"

Arthur paused, one of his gloves halfway on. "When do I ever hit you?"

"All the time," Merlin replied.

Arthur heaved a sigh. "That's not hitting, Merlin. That's merely friendly slaps. It's horseplay."

Merlin got that mischievous glint in his eye. "So, can I give you a friendly slap?"

"You can certainly try," Arthur replied, turning back to his armor. A moment later he felt something whack him across the back of the head. He pivoted slowly, turning to face a slightly nervous Merlin. "What the hell was that?"

Merlin swallowed. "It was, um… horseplay."

Arthur raised his eyebrows. "No, Merlin, you're doing it all wrong." He pulled on his second glove and clenched his hand into a fist. "Why don't I show you?"

Merlin's eyes widened as he stared at the glove, then flicked his gaze up to Arthur.

Gotcha.

It was both difficult and annoying to get armor off, especially when you were in a hurry, but they managed with minimal damage to life and limb. Arthur didn't trust the durability of the walls, not after that one time, so he pushed Merlin down onto the ground. "You think you can keep quiet this time?" He asked, undoing Merlin's trousers.

Merlin bit his lip and then reluctantly shook his head.

"Right." Arthur grabbed his discarded glove. "Open."

Merlin opened his mouth obediently and let Arthur insert the glove in, biting down hard. Arthur had a feeling there'd be bite marks permanently marring the leather, and the thought made his cock twitch. Merlin tried to say something, the words obscured by the mouthful of leather, but Arthur was pretty sure he said I don't think this falls under the definition of 'horseplay'.

Arthur rolled his eyes. "Like you were any good at it anyway."

He nicely cut off Merlin's reply by thrusting into him and making him choke on his words. Merlin's hands automatically flew to Arthur's back, nails digging in to leave small red marks that Arthur could secretly grin at in the mirror that night. Once, a few months after he and Merlin had started having sex, he'd wondered if he would ever tire of Merlin, and had fervently hoped that he wouldn't. Now, he knew better.

It was impossible to tire of him.

And while Merlin made the best noises, Arthur was finding he liked this gag option, too. Merlin made tiny little whines in the back of his throat and gave out muffled groans, his eyes rolling back into his head and his fingers sliding through the sweat on Arthur's back, marking him up. The best part, though, was when Arthur could feel his climax building, that glorious rush bare moments away, and he yanked the glove out and kissed Merlin until his head spun. Merlin made a kind of panting scream into Arthur's mouth and came hard enough to arch off the ground, shuddering violently.

"That," Merlin panted. "Was not horseplay."

Arthur rolled his eyes and struggled to his feet. "Shut up and help me get back into my armor."

For the second time that day, Merlin whacked him in the back of the head.