I think I kind of imagine this in an au of mine that I'm unlikely to write out, but you don't need to know the details of that to read this.
I'd also like to add a small warning for a possible past abuse trigger. It's not meant to be that specifically, though it is close, so I won't be adding it as a tag, but I'm concerned some readers might be upset because it does come across that way. I'd rather people be aware and comfortable.
There are no mentions of what happened or any descriptions of such, even by implication, but it's the imprint on Arthur's emotions now.

Arthur stared, the quietness of the room resting heavily over him like the stillness of the dark. It seemed silly, a little while ago he'd been flush with warmth, an overpowering joy and fondness, but now he felt cold. From that angle, there wasn't much of a view out of Alfred's window, just the sky, interrupted by buildings and made uninteresting with clouds. Perhaps if they'd been heavier Arthur could've hoped for rain, but for now everything felt dull.

He was aware he should sleep, unsure what time it was and unwilling to turn over in search of his partner's alarm clock to tell him of the time. He'd slept a long while anyway; he could feel it in his bones. But he didn't want to look at Alfred. Part of him reminded himself this was ridiculous, a louder part told him how much Alfred cared for him, but the clearest voice told him he was wrong. Alfred's soft murmurs those hours ago still echoed in his mind, the warmth and affection felt deep in his core when Alfred looked at him like he was the only thing on earth that mattered – because Alfred's eyes hadn't strayed from his own when he told him he was beautiful. Something deep inside him ached; making him pull the corner of the duvet closer to his chest, screw his eyes tight. It felt like a trick, some awful, horrible trick because he couldn't belong there in that bed just as precious as Alfred said he was. Someone else would've told him the same thing if it were true.

"Arthur?"

Alfred's voice was soft, groggy, but enough in the silence to stir Arthur rather violently out of his thoughts. He said nothing, unsure if he wanted to pretend to be asleep or if he'd simply lost his voice. He heard movement behind him, the creak of the mattress as Alfred shifted but he couldn't tell the alpha's intentions until two arms slid softly around his waist.

"Everything okay?"

The words were still soft, somewhere close behind his ear and Arthur was sure he'd never been so aware of every muscle in his body before that moment. He felt so tense. He was tense, he was sure Alfred could feel it. He could probably smell it, whatever it was in a muddled discomfort of Arthur's scent the alpha was sure to have detected it. Had that been what stirred him from sleep, too? Was that Arthur's fault?

"You don't have to tell me." Alfred murmured, effectively cutting into Arthur's thoughts again. "You don't have to tell me anything you don't want to…I just want to make sure you're okay."

Arthur paused, eyes open again as he weighed the meaning in Alfred's words. Alfred was so sweet, so considerate – how was he to know if it was genuine or not? He felt guilty for the thought, for doubting Alfred even for a moment. But it was so late at night, so many things had happened, he wasn't sure if he could believe that. He felt a lump in his throat, aware all of a sudden that he'd been quiet far too long and everything felt so heavy in that swift moment, until those arms brought him closer and he felt a warm body against his back, cradling him, holding him.

"I won't let anything happen to you—" Alfred's voice registered in the back of Arthur's brain and the deep breath that followed from his own throat felt far too thick and caught for his liking.

"—Can I have a shirt? A…And my boxers-?" His voice was far softer than he'd wanted it to be. Or maybe just expected. There was something hazy and distracting in that hour and Arthur couldn't tell if it was the time or just his mind.

"Of course."

The arms were gone in a moment, but Arthur didn't move even as he heard Alfred shuffling around and the opening and closing of drawers. He closed his eyes, taking it in for a moment before he slowly lifted his hands to his face, running them down and up again. He didn't feel awake, but he didn't feel asleep, sleeping had far too much rest in it and he felt himself in some limbo in between. With a little effort, he pushed himself up, sitting slowly and letting the cover pool in his lap.

Alfred had a pair of boxers on that Arthur was sure he wasn't wearing moments ago, but he turned at the sound of movement and Arthur had to stop himself from pulling the duvet up around himself when Alfred smiled softly at him. He walked over to the side of the bed, one of his own shirts and Arthur's previously discarded boxers offered out to him.

"I can find your shirt if you'd rather have that-"

"No. No I, this is fine."

He wasn't sure where he found a smile, but he looked up to give Alfred one. Far smaller than the alpha's own, but there was a kinship in the softness there. He took the clothes and Alfred turned away, moving across the room again and Arthur didn't look up to see what he was doing. He slipped the shirt on, aware he liked the smell of Alfred's clean laundry, well aware he liked the soft cotton against his skin, too aware he liked the safety he smelt in the alpha's pheromones. The boxers took a little more wriggling, but he found something uncomfortable in the idea of pulling the covers off to put them back on so he didn't, wriggling about to get them on the hard way. Alfred definitely saw, but when Arthur looked up the alpha had a shirt on of his own (far better fitting on him and Arthur suddenly wondered if he looked stupid or ridiculously small in Alfred's larger shirt) and was moving back to his side of the bed.

Arthur stayed sat up, watching him sit and pull the covers over his own lap. He said nothing, finding himself staring at Alfred's joined hands, unsure what he wanted to say. But Alfred always seemed to have that covered.

"Is that better?"

Arthur looked up, catching the mixture of emotions in Alfred's eyes and almost feeling the need to slide across and reassure him. He offered a small smile instead, just a slight tilt in the corner of his mouth.

"Yeah…Thank you."

"It's okay." Alfred sighed, his own soft smile returning. "You don't have to thank me."

Quiet fell again, though this time it felt heavy, no evidence to say Alfred would be breaking it again. The chill that had disappeared for just a moment with Alfred's arms around him wormed its way back in again and the omega found himself clasping his own hands in his lap. Alfred looked up too quickly and he knew right away it had been his scent that disturbed the alpha, but this time he said nothing. It took a few long moments, but Arthur soon slid across the space between them and before he knew it he was curled against Alfred's side with the alpha's arms around him.

He let his forehead rest on Alfred's shoulder, an odd position, surely not comfortable for either, but Alfred didn't complain. He just sat there, holding Arthur close.

"Did you mean it?" His voice felt more like a whisper, a breath, mouthed so quietly against Alfred's shoulder he wasn't sure if the alpha even heard him. "The things you said, when we- when we were…Did you mean it?"

"Every word." Alfred spoke back just as quietly, Arthur wasn't sure he wanted to know if it was because Alfred was just reacting to what he said or because he didn't want to embarrass him. It didn't cross his mind that the alpha just didn't want to disrupt him. "…Should I— Should we not have-"

"No-!" Arthur spoke too fast, lifting his head and feeling instantly embarrassed when he met Alfred's eye. He cast his gaze down again, fingers curling into Alfred's shirt. "No…No that, that was good. It was, I wanted to, really. It was really good." He lowered his head again, resting closer to facing the alpha's neck this time. "It just…Things feel weird."

Alfred stayed quiet, running a hand up and down the omega's back, something comforting and encouraging in the touch.

"…I'm," Arthur stopped himself again, not sure what he wanted to say. Not sure he wanted to say anything at all. "It's not like this. It hasn't ever been so…Like this. Alphas don't- they don't usually…" Again he trailed off, his grip on Alfred tightening before he could really think about it.

"You don't have to say it, not if you don't want to." Alfred said, holding Arthur just a little closer.

"I want to." Arthur whispered back. "I want to…I'm not used to alphas doing- treating me like that. Like I-" He lost the word, floundering with a breath of frustration for a moment before Alfred spoke again.

"Like you matter?" His grip tightened and Arthur couldn't help feeling that lump in his throat again as he held tighter to Alfred too. He nodded, all too aware of the way Alfred rippled – like he was trying to control himself, stop himself from acting. But for once it didn't feel like a bad thing.

"It's," He closed his eyes, flexing his fingers like he needed to think. "I know- I know you mean it. I know you wouldn't lie to me, especially not for that and some part of me wants to hold onto you forever just for that but—but some of me is trying to tell me that too is a lie…Like you're no better than any of them." It was odd to find his voice then, find more sound in those words than the whispers of before, but perhaps it was the way Alfred couldn't seem to help holding him tighter, even if they both twisted uncomfortably to hold each other.

"…I don't ever want to hurt you, Arthur." Alfred was quiet this time, not soft in the way he'd been to match the omega's tone but something purer. Something raw. "I couldn't. I don't want you to feel- afraid if you're here with me, I don't want you to wake up in the middle of the night wondering if what I said was real or not."

"Me too…" Arthur murmured, sitting there in Alfred's arms for a moment.

"…Is there anything I can do?" It was small. The sound in Alfred's voice; small. It resonated deep in Arthur, that openness the alpha had right there to him, only him, inviting him closer. He lifted his head, drawing back enough to meet Alfred's gaze.

"…I don't think there is. For now."

He saw Alfred swallow, the bob of his Adam's apple as he nodded, breathing for a moment, resting his forehead against Arthur's. Arthur sat there, eyes slipping shut as he pressed back, feeling Alfred's nose bump his, Alfred's arms pull him close, Alfred's heartbeat under his hand. That scent, the warmness, summer and pine and clean sheets and coffee and sweat, safety – it washed through him in a moment.

"Can I tell you everything again while you still believe me?"

Arthur's lips curved up, gently, pressing fondness there before Arthur's eyes even opened. He searched Alfred's eyes, seeing only something he couldn't quite place. Something he hadn't ever seen in any alpha's eyes, not something they ever looked at him with. Not something anyone wanted to throw his way. It caught his breath, made his whole being soften towards Alfred.

"—I think that would be okay." His voice had dropped to a whisper again, but there was a smile in it, a playfulness as if their talk hadn't been resting heavy on both their shoulders. And it was nice. To roll it off, get lost in Alfred's eyes and his warmth and his arms.

Alfred grinned, falling back against the pillows and pulling Arthur with him and the omega couldn't be bothered in that moment to complain. He shifted though, letting Alfred pull the sheets up and then he curled against Alfred's chest, his arms around the alpha and the alpha's arms around him. It felt good to be held, felt better to breathe in Alfred's scent; felt best to hear his soft murmurings as he drifted back off to sleep.