"Do you listen to a thing I say?" Merlin closed his eyes for a moment, and breathed a small sigh. How many times would he have to reassure Arthur of his trust? For someone who had struggled to do something so small as call Merlin friend, and privately no less, between only the two of them. Merlin doubted Arthur had ever referred to him as such in conversation with anyone else...And yet, he felt entitled to all of Merlin's secrets, and was hurt when he discovered that Merlin kept some for himself. Usually out of the desire to live or protect Arthur himself, one might at.
"I trust you, Arthur. I trust you. I trust you with my life." Merlin started. "Need I say it again? I trust you." He lifted his head and looked at Arthur patiently, speaking in soft, calm tones that showed both how tired he was (enough to keep any frustration or annoyance that might have been in his tone otherwise) and was perhaps a little coddling.
"My worst fear was losing control of my magic and hurting you. I was afraid to let you see me like that. So I hid. It wasn't because I didn't trust you. I didn't trust myself not to hurt you is all." Merlin wasn't about to admit he had in fact jumped out the window to avoid Arthur when this began, but there it was. He also avoided mention of his constant nightmares during the whole ordeal, ones that he had on occasion regardless of so called demons to stir them from the place in the far back of his mind that Merlin tried to force them.
"Why do you care so much if I trust you or not anyways?" He ran an idle hand through his hair, and looked elsewhere -- anywhere but Arthur as he continued, particularly at the floor. "It's not as if you trust me. Sometimes I wonder if you care at all either way, and just keep me around to entertain you because I was so awful at being a servant, and one of the few people back home who would be honest with you when you were being a prat. And here...Well, I see to your food, and get your clothing washed, and beyond that -- we've done nothing but argue if we speak for too long."