Warnings: Light dom/sub, spanking, sexual content

A/N: First canon era Merthur ever, and it's a PWP. Figures.

~oOo~

It happens just after they're dismissed from the Great Hall. Amid the knights and council members sweeping by, Arthur fixes Merlin with a look.

"I require some milk and honey for my sore throat. Bring it up to my chambers."

Merlin swallows, whole body suddenly prickling with heat as he hears the magic words. Innocuous to anyone else but him and Arthur; sounding for all the world like a standard order from a Prince to his manservant.

But Merlin knows better and he trembles in anticipation.

There's no particular pattern for when Arthur issues the command, but it often seems to come at the end of a week when Merlin is overworked and tired, when the demands of his job have begun to wear on him a little.

Arthur never acknowledges this to be the case, but Merlin notices it all the same and he's grateful. The Prince somehow knows when they both need this the most.

He hurries off to the kitchen to fetch the cup of milk; requesting an extra drop of honey as he likes the sweetness, and he knows Arthur won't be the one drinking it later.

He sets it down on the table when he reaches Arthur's chambers, being sure to lock the door behind him. The Prince is already in position, sat in a chair in the middle of the room, book balanced on the arm rest.

He eyes Merlin lazily.

"Strip," he says.

Merlin tugs off his tunic with shaking fingers, letting it fall to the ground. He unlaces and sheds his breeches quickly and then hooks his fingers into his underclothes. He pauses for a second and Arthur quirks an eyebrow.

He drops them.

"Come here," Arthur says.

He walks over and stops in front of Arthur.

"Turn around."

He turns slowly.

Arthur reaches out and jerks Merlin down backwards into his lap. Merlin is completely passive as Arthur arranges him to his satisfaction, pulling Merlin's back up against his chest and draping his legs over Arthur's own, letting Merlin's head rest against his shoulder. When he's content with the position Arthur wraps one arm around Merlin's stomach, to hold him in place. With his other hand, he picks up his book and begins thumbing through the pages, resting the bottom of the spine on Merlin's thigh.

Then he reads. In silence.

As though Merlin isn't even there.

Merlin manages to keep still for about two minutes before he starts to squirm. He doesn't know what it is about this particular position that turns him on so much, but he can't help himself. Something about the way his naked skin feels against Arthur's fully clothed body. Something about Arthur's hand around him, trapping him in place. Something about the way Arthur strips him and then totally ignores him, as if Merlin's just some rag doll perched in his lap. It sends shivers of humiliation down his spine - which then uncurl into tingles of arousal heading straight to his cock.

Arthur turns another page and Merlin lets out an involuntary moan.

"Shhh," Arthur says dismissively, eyes never leaving his book.

Merlin bites his lip, wanting to obey. Wanting to be good for his Prince.

But it's so difficult. Five minutes later and he's shifting again, his cock hard and jutting forward, mere inches away from Arthur's hand. If the Prince moved it, just a little, he might get enough friction to get some relief…

"Stop wriggling," Arthur says.

"I can't," Merlin bites out, suddenly desperate.

"You can, and you will," Arthur says, supremely unconcerned.

Merlin bows his head, determined to do better. They both know the rules of the game and it's not unintentional that the odds are stacked completely against Merlin, but he still has to try. There's pride at stake. He shouldn't be made to beg so soon.

He lasts for another five minutes. Then it's just too much, even the feel of the air on his oversensitive skin is more than he can bear.

He grinds back into Arthur's crotch.

There's a pause and then Arthur slowly puts his book down.

"Am I to take it you're giving up?"

"Yes," Merlin grits out, all pride gone. He wants to be touched, now.

"But I was enjoying my book," Arthur says calmly. "You interrupted me. So if you really want to start now, I'll have to punish you first."

His fingers ghost over the little groove made in Merlin's thigh by the book.

"I'll have to spank you."

A shiver goes through Merlin's whole body, but it's not from fear.

He nods.

"What do we say, Merlin?" Arthur asks quietly.

"Please. Please spank me."

"Very well."

Then Arthur's manipulating his body again as though he weighs nothing; draping him face down across his lap, one hand at the small of his back.

"You shouldn't interrupt the Crown Prince when he's busy, Merlin."

Arthur's hand begins to massage his arse, slow and steady.

"You need to be taught some manners."

Smack.

Merlin lets out a whimper at the first impact. Arthur doesn't hit hard but there's something so precise about the way he lays the blows, a little sting that jolts all the way through him.

Smack.

His cock is still hard and pressing into Arthur's legs.

Smack.

Every hit drives his crotch further into the Prince's body. He can't help but hump forward a little bit, moaning.

"Naughty boy," Arthur says softly above him.

Smack.

The blow is slightly harder; a reprimand for not controlling himself, but it doesn't stop Merlin from grinding his cock downwards again.

Smack.

Merlin has a sudden image of how he must look to Arthur; naked and squirming and arse rapidly pinkening. He feels that funny tingle of arousal/humiliation again and it's enough for him to abandon all semblance of dignity.

"Please," he whines and Arthur pauses.

Then he hears the familiar sound of the Prince reaching into his pocket to take out the vial of oil.

"I hope you learned your lesson," he whispers, uncorking the bottle, and Merlin tenses in expectation.

The first trickle of cold oil between his cheeks makes him quiver. Then Arthur's spreading his legs, as much as is possible when Merlin's still draped over his lap, and exposing his hidden opening.

Another agonising pause and then he groans as Arthur slides one slicked up finger inside him. Arthur doesn't make him wait long for another, pushing them both far enough in that Merlin's toes curl up.

He scissors them expertly and Merlin thrashes. Arthur's free hand moves to press down on his back, holding him still.

"More…" he gasps out and the Prince obliges, slipping in a third. All three digits bump up against the sensitive spot inside him that Arthur unerringly finds without fail.

The stimulation makes him heady, dizzy.

"Please, I need more," he says urgently, wanting the Prince to sit him up now and fuck him properly.

"Not today, Merlin. Today you're going to come on my fingers alone."

Merlin almost screams in frustration. It's not enough, he needs something bigger.

"You can do it. Trust me."

He can't. He's grown so used to always finishing on Arthur's cock, how can he settle for less now?

But he's been told to trust his Prince and he has to try.

So Merlin lets his hips jerk spasmodically, rubbing his naked cock against the fabric of Arthur's breeches. Arthur's rhythm has speeded up. He's relentless, thrusting his fingers in and out, pushing up against the sensitive place again and again.

Arthur's technique is so skilful, so on the mark with every single thrust that Merlin starts to believe it might be possible. He gives himself over to the sensations, concentrates on the feeling of Arthur's fingers fucking mercilessly into him.

He grinds down harder and Arthur's free hand slips off his back to lightly spank his buttocks again. The sensation tips him into a frenzy, rocking his hips back and forth to push his throbbing cock further into Arthur's body.

Arthur adds a fourth finger. Merlin comes with a strangled cry.

The Prince pets him through his orgasm, stroking his back as Merlin pants and moans, limbs curled tight in ecstasy.

Then he's gently lifted to sit upright in Arthur's lap again, the comfort of the position outweighing the twinge of resting his weight on tender skin.

Arthur feeds him the cup of milk and honey, tipping it into his mouth until Merlin is sated and content, resting his head back against Arthur's shoulder.

"You did so well," the Prince murmurs. "My Merlin."

"My Arthur," Merlin says, sleepy, happy.

Then Arthur picks up the book and reads aloud until Merlin is lulled into a restful slumber.