Merlin was pushed onto his knees before the king by the guards excorting him.
"Leave me," Arthur ordered the men.
"But my lord," one began. "He's a sorcerer."
Arthur nodded. "I am aware. If he intended to kill me, wouldn't he have poisoned my food when he had the chance?"
The guards shrugged and left.
Arthur turned his attention to Merlin, pain clear in his eyes. "How could you? I trusted you, Merlin."
Merlin looked up, his gaze confident. "My magic has saved your life more times than I can count, sire."
Arthur sighed, his head dropping into his hands. When he looked up again, his expression was hard and determined. "You knew your crime. You will be punished for it. Guards!" he called, and they returned. "Take Merlin to the dungeon. I shall be there shortly."
Merlin waited silently in his cell, his back firmly against the wall for some time. Finally, Arthur's footsteps echoed down the stairs, and his voice boomed. "Guards, leave."
There was some argument from the guards again, but they relented and followed their orders.
Moments later, Arthur appeared at the cell door, keys jangling. He unlocked the door and pulled it open with a loud creak. "Get up," he ordered, but Merlin didn't budge. "Now!"
Merlin refused to move.
"I am your king," Arthur shouted. "You will obey me!"
Merlin looked up at him, meeting his glare evenly, but still did not stand. "If I am to die, I will die with dignity."
Arthur laughed. "You most certainly will not." He moved to Merlin and yanked him up, pulling him to another area of the cell and shackling him to the wall.
Merlin's arms were suspended above his head, and his feet were secured to the ground, but he still held Arthur's gaze, insistent on dignity. Arthur stepped back, and, facing Merlin all the while, made his way out of the cell and brought a cart from around the corner.
Curiosity got the better of Merlin, and he strained to see what was in the cart, but he couldn't.
Arthur smirked. "You want to know what I have planned, do you?" He pulled a knife from the cart. "Well, you'll just have to wait and see."
Merlin tried not to flinch as Arthur brought the knife to his neck, but didn't succeed.
"Oh, stop that," Arthur said. "I'm not going to kill you now." Instead of slitting Merlin's throat, he drew the knife down, barely scraping the skin and not drawing any blood. Then, he sliced down Merlin's tunic, revealing his chest and stomach.
Merlin gasped in surprise, giving Arthur an opening to shove the gag he held into Merlin's mouth. "I don't want you attempting any magic on me," he explained as he knelt, pulling Merlin's trousers and underwear to the floor. Merlin blushed as Arthur held his naked cock in his hand, gently pulling and rubbing it until it was sufficiently hard. He then pulled another device from the cart- a collection of leather straps- which he secured tightly around Merlin's now nearly rock-hard member and balls.
Merlin furrowed his brows in confusion until Arthur whispered the purpose in his ear- Merlin would find it very difficult to climax until those leather straps were released. Merlin's eyes widened as he realized just how much torture he was about to undergo.
Arthur knelt again, placing Merlin's cock into his mouth and taking it deep into his throat. Merlin groaned against the gag as Arthur ran his tongue up and down his cock, flicking it over his head every once in a while. Eventually, Merlin began begging Arthur to undo the straps, and, even though he couldn't understand a word Merlin said, he understood the meaning, and popped Merlin's cock out of his mouth.
"Well, aren't you just the most selfish criminal?" Arthur purred. "Don't I get to have any fun?" With that, Arthur removed all of his own clothing and loosened the fastenings the held the chains onto the walls and floor, so that more chain could pull through.
"Step forward," he commanded as he stroked his own rapidly hardening cock.
Merlin did as Arthur asked.
"Now bend over."
This time, Merlin was hesitant, but complied when Arthur glanced back to the cart threateningly.
Arthur moved behind Merlin, positioning himself only momentarily before thrusting into Merlin's tight little entrance. Merlin groaned in some mixture of pain and pleasure that became more pleasure as Arthur continued to thrust harder and faster.
Arthur heard the sounds Merlin was making, and was only spurred on. When he could feel himself reaching climax, he only continued with more fervor.
He exploded inside of Merlin, then removed himself, covered in his own sticky white substance. He returned to Merlin's front side, and Merlin began to stand.
"Stop," Arthur said. "Did I ask you to stand?"
Merlin shook his head.
"Then why would you?"
Merlin bent back over.
"Clean this up," Arthur ordered, removing Merlin's gag.
Merlin flicked his tongue out, tasting Arthur, before engulfing him in his mouth. Once his member was clean, Arthur pulled away.
"You've taken your punishment well," Arthur said. "Now it's time for your reward. Stand up."
Merlin stood eagerly, and Arthur resumed his work, pumping Merlin's cock in his hand as he ran his tongue over its tip until Merlin began moaning his name and begging again. Then, finally, Arthur released the straps, allowing Merlin to experience the most overwhelming climax of his life. Arthur swallowed down every last drop before unshackling Merlin and leaving with one promise.
"I'll be back tomorrow, to resume your sentence."