This was written before chapter 42 came out, and I thought the demon state was permanent. I also took some liberties with how Yuu would act as a demon, so be warned for that.

It was dim in the room after Mika shut the door. The light filtered through the curtains that fluttered every so often when wind breezed through the tilted window. Yuu was lying on the bed, eyes closed, breathing evenly. It would make a nice domestic picture, if not for the chains coiling around his arms. And the horns. Mika knew from experience that those weren't just for show. He scratched his shoulder out of reflex, but both the pain and the scar had already faded days ago.

He silently stepped closer, still on guard until he was sure Yuu was actually asleep and it was not a feint. The demon had tried getting at him before, which was strange, because he never seemed to go for any of the others. That hurt more than he wanted to admit. That was also the reason for the open window: it was on the opposite side of the room, too far away for Yuu to get to with his chains, but the others would hear if Mika called for help.

Right now, Yuu really did seem asleep, and Mika relaxed slightly. He put the food and water down next to the bed and made to go back, but he hesitated. Yuu looked so peaceful like this. He stretched out a hand, but stopped inches before Yuu's face. What was he going to do? Brush away the hair? Touch him? Was he insane? If the demon woke up, he'd be in immense trouble.

He made to pull away, but a hand caught his wrist, pulling him down and away and before he knew it, his back was against the wall, his arms pinned and his vision was filled with red eyes. He tried to wriggle away and push Yuu off, but the grip didn't loosen in the slightest. A shiver ran down his spine. Ah, this is dangerous. Instead of murderous intent though, the only emotion he could read on the face in front of him was surprise.

"Hah. That actually worked. You really did fall for that."

It was the first thing he'd said in days. He sounded so much like Yuu when they were younger that his heart ached. Mika wanted to look into those eyes until he could see through the demon and beg him to come back. He wanted to scream at him. He wanted to - instead, he said: "One shout from me and the others will come running in."

"But will you…?" Lips curled up in a grin. Mika felt his heart race - fear. "What." he gritted through his teeth. "Shout." The face came closer, breath ghosting over his lips, cheek, ear. "Why haven't you?" Mika made another attempt to break free, but they both knew it wouldn't be of any use.

Yuu sat back, but the grin was still on his face. Mika would call it devilish, but that was such a cliche.

"You know I've always wanted to try this, but I never really dared to. I can't really see why anymore though."

Fuck, what is going on, damnit.

"You should let me go Yuu. You're not yourself." Mika tried to sound calm, but there was a big chance the demon could hear his heart racing, too.

He seemed to find that amusing. "You're wrong, Mika. I am me. Just not hindered by stupid conventions to hold me down."

"Stop it. You don't want to hurt me." He wanted to say 'you wouldn't', but that wasn't true anymore.

The demon laughed again, surprised. "That's what you think? Ah, I see. You've been trying to convince yourself that you're just scared. It would be a normal reaction. But you can't deceive me, Mika. We demons live on lust. It's easy to recognise."

Mika's thoughts raced. He wanted to deny, grasped for a real reason his breathing hitched at those words, a reason for biting his lips when teeth grazed his neck, just enough pressure to feel it, not enough to break skin, a reason for trembling arms.

He felt cold steel against his own wrists, pulling him down on the bed, trapping his hands and he swore his first reaction was thinking how is that possible and shit he somehow pulled that chain out of the wall. Certainly not excitement.

"Stop denying, Mika." Teeth were at his ears again. "Don't you want to have some fun?" Hands roaming over his body, over his tights, ghosting over his crotch, just feather light touches, then his belt buckle, and - stopped. Mika's eyes shot open, never realising he'd closed them. The ones in front of him were still red, but the face was honest, open, questioning.

Is he really…? That was a real question? Was that a demon asking for permission? He felt his cheeks flood with colour. Turning his head away, he awkwardly hid his face with his arms. Trying to calm his breathing, he mumbled: "Y-yes…" Then a little louder, a little more sure, "Yes. Please."

He heard a sharp intake of breath, excited, and Yuu nuzzled his neck with his nose. Mika could hear a noise of contentment, maybe even relief. Yuu's hands started moving again, not on his trousers, but up, opening his vest and pushing it away. His mouth moved down over his collar bone, biting softly and licking, cold air prickling Mika's skin on the trail that he left.

He gasped as teeth bit down on a nipple. Yuu teased it softly, pulling on it, then sucking before going on to the next one. His hands travelled down again, short nails raking over Mika's abdomen, he could feel goosebumps on the skin.

He palmed Mika through his trousers, softly, slowly, and Mika groaned, pushing up his hips for more friction, but Yuu pulled his hand away just enough to keep everything agonizingly just not enough. "Don't tease," Mika managed to gasp. His belt clicked open in no time, button popped, zipper pulled and Yuu's hands slid under his briefs to pull down his trousers. He squeezed Mika's ass in passing and Mika forgot he was wearing those damn boots until everything got stuck. Yuu let out a frustrated growl. The look on his face was almost endearing, like the demon had thought out this perfect plan than now got thwarted by a pair of stupid shoes. Mika just kicked them off.

"Thanks," Yuu whispered, and that, that was completely endearing. Mika's heart melted.

With the trousers finally gotten rid of, Yuu sat back on his heels, looking at Mika as if he'd just finished an artwork, staring in awe of what he had created, almost not being able to believe his eyes. The red on Mika's cheeks deepened. "Yuu…" he mumbled, and Yuu blinked as if snapping out of a trance. He grinned again.

"I'm sorry, I didn't mean to make you wait," he drawled out, his voice a low rumble. Entirely too sexy for an apology. Not breaking eye contact, he slipped three fingers into his mouth, licking them sensually, touching himself with his other hand. Mika swallowed. His throat suddenly felt dry.

It didn't take long before Yuu crept closer again, looking Mika straight into the eyes with one eyebrow cocked, as if to say "watch me", but Mika was distracted by a finger at his entrance, circling a few teasing rounds, before slipping in like it was nothing. It was slicker than he'd expected, but he quickly wrote that off to demon saliva or whatever. He wasn't complaining. His thoughts were shut off completely by a second finger, quickly followed by a third. It was a strange feeling, but his body quickly adjusted, taking the fingers easily, making him want more. He tentatively rolled his hips and nearly screamed when the angle changed and Yuu found his prostrate. He vaguely remembered the open window.

"So eager. And a lot more honest now. I like this part of you much better," Yuu drawled, "but this is not everything." He took out his fingers and Mika groaned in frustration at the empty feeling they left. His cock twitched when a hand brushed it, then sliding up the underside of his tigh, hooking a knee over Yuu's shoulder.

Without further warning, Yuu entered him and Mika thought he saw stars. He didn't remember Yuu pulling down his pants or lubricating himself, but for now, he couldn't care less, because Yuu was in him and moving and oh God… Despite the slow pace he'd started out with, it was rough. Yuu didn't wait for Mika to adjust and he could feel twinges of pain, blended with the pain he felt in his wrists when he pulled a little too hard on the irons, but it melted together into deep pleasure.

Yuu's mouth was at his ear again, nipping and growling, but then it moved to his shoulder and placed a soft kiss there. Mika didn't know if it was his imagination or if Yuu really did whisper "sorry" then. A real apology this time. He felt tears spring into his eyes because wounds and scars had already healed and there was nothing there to see, but that was the exact spot horns had pierced skin not a week ago.

Emotions mixed with lust when Yuu changed his pace and he wanted to cling to his shoulders but he could only cling to his manacles and whisper more more more. He bit his lip to stifle his moans when Yuu adjusted the angle and hit that spot again but then slowed down. Again. Mika tried to roll his hips to create more friction, because he was so close, but there was a hand there, keeping him still, almost bruising and Yuu growled in his ear as if to say "I'm in control. You'll come when I want you to." Mika didn't know if it was possible to be any more turned on.

The pace was agonizing, and his body was tingling all over, waiting for the speed to catch up, waiting for his release. He could feel Yuu was having trouble too, straining to keep slow, trying to draw it out as long as possible, until he finally gave in. The bed rocked with the sudden change of pace, but Mika could care less, because Yuu seemed to know exactly where his prostate was and how he should hit it and he came without a warning, not entirely able to still his moans.

His body spasmed and that must have brought Yuu over the edge. They rode out their orgasms together.

Afterwards, Mika rubbed his arms as bruises were already forming and fading where the irons had cut deep. When he looked up, Yuu was staring at his bottom lip. No doubt it looked red and swollen from Mika biting it. He opened his mouth, but before he could say something, he felt other lips on his, then teeth as Yuu bit down hard. He could taste his own blood on his tongue.

"You're mine now," Yuu growled, as if Mika could just walk away and forget.

Yuu made to let him go, but Mika pulled him in again, lips softly brushing together this time. "I've always been yours." For a moment, it was as if the eyes in front of him changed back into green, but it must have been his imagination, because when he blinked, they were red again.

Ok guys, this was my first time writing smut, so I hope you all enjoyed it!
Critiques are always welcome :)