Merlin cant remember how it started. Sure, he can remember the how, but maybe it was the why that was somewhat trickier to grasp onto. It seemed as though they were both minding their own business, cleaning boots and attending to the paperwork that appears to come with the job title 'Prince', and the next, palms, teeth and nails were being dragged accross hot, sweaty skin through desire and need for release. When it was over they laughed, Arthur fixed his hair till it was just so and Merlin adjusted his neckachief so no one would see the telling red marks on his pale skin.
They didn't talk about it, they acted as though everything was normal, and in an odd way it was. Two nights later when Merlin was summoned to Arthurs chambers whilst the rest of the castle slept, he didn't bat an eyelid. He didn't knock on the door when he entered, didn't wait for Arthur to say anything before he pulled his tunic over his head, didn't kiss Arthur as he did the same to him and pulled him ontop of him, onto the bed. Didn't cry out Arthurs name whilst clinging to his back, finding his release. Didn't stay when Arthur fell asleep. Because that was normal. It wan't about kissing and softness and love, it was about need, hunger and desire, filling that primal urge. Their need equalised them, no longer princes or heirs or servants or warlocks, just two young men that wanted so badly.
It did change eventually, it had to change. Arthur kissed him. He came to Merlin's room on the night of his wedding to Gwen, Arthur had never come to his room before. They stood together in the dark, holding each other against the world, and Merlin placed his hand on Arthurs cheek, turning his head to look at him. Arthur knew what was being offered and took it, his lips soft and sweet, and Merlin could taste Guinevere on them, but he didn't say anything and he didn't stop. They had been together so many times before and Merlin knew it would be differnt, but never so differnt as it was. When it was it was over, Merlin had to bite his tongue and hold back on the urge to to hold Arthur to his chest, instead pulling him up off the bed and dressing him and pushing him out of his door, ignoring pleading eyes. Because they weren't equals and they didn't just need a release.
Arthur always came to him after that, presumably in an attempt to protect Gwen from the truth, but Merlin knew she knew, even before they married. The other servants gossiped and talked of how often Merlin was called to the Prince's chambers and how late it was when he was seen leaving. The Knights knew, probably before even Arthur did, so accustomed as they were to reading his moods and his actions. They noticed the subtle changes when Merlin entered the room, or when he waved at Arthur across the training grounds. They saw through Arthur's mocking and condoning and noticed his softening features when he glanced in Merlin's direction and how he always seemed to linger without noticing whenever he touched Merlin. They all talked in hushed tones, but Gwen heard and stood silent. She never said anything but she couldn't quite meet his eyes when they spoke, and she no longer dropped by to talk.
A few months after the wedding, Merlin was stopped from preparing Arthur's breakfast by the cook and told that he had a new manservant now. Merlin smiled and nodded and left the kitchen, breaking into a sprint towards the room he knew so well, wanting just to hear Arthur tell him it was a mistake. He didn't knock on the door. Arthur wasn't waiting for him. Gwen looked up from the table and looked at him expectanly and he knew it was her. She told him he would spend all his time with Gaius now, and that he wasn't to see Arthur any longer. Merlin nodded and walked away.
It didn't work. Arthur came to his room almost everynight and snuck away from his duties whenever he could, just to lie on Merlin's bed with his head on his lap and feel the strong fingers play with his hair and listen to Merlin's ramblings. And it only made it worse.
More people began to notice their King's odd disappearances and the hushed gossip was no longer hushed. Merlin knew it would not last much longer, and that soon their world would crumble apart. But for now, he would be content, with his love's head in his lap and his fingers curled in golden hair, wondering how it all began.