Set somewhere in the current timeline-ish of the manga. The first time they went to Ferid's mansion. In case there's a second.

"Mika, I missed you," Yuu whispered in Mika's ear, wrapping his arms around him from behind.

Mika immediately stiffened. "I missed you too." He said, afraid of setting the demon off.

Maybe the demon thought that he wouldn't notice, but he could tell just by the slight difference in Yuu's tone and voice that he was a demon.

Mika shouldn't have left him alone. They were going to get some fresh air, they couldn't stand to be in that place any longer, Freid's mansion, at least Mika couldn't. Yuu honestly hadn't seem all that bothered. Yuu was strong, stronger then Mika. Yuu said he had to go the bathroom and he didn't need Mika to babysit him, so Mika listened and went on ahead. He didn't think he'd be greeted by a demon when Yuu came back.

The demon chuckled. "What were you planning on doing, playing along until I told you?"

Mika frowned, before escaping Yuu's arms and turning around.

"Did something happen? Why are you a demon?"

"You didn't answer my question," Yuu said harshly.

"You didn't answer mine," Mika replied.

The demon growled, before pulling Mika toward him by his collar.

"Are you trying to agitate me? If you have a problem just say it."

"I want you to change back into a human."

The demon smirked wickedly. "I'll change back when you do."

Mika glared at him, Yuu wasn't sure if he'd turn into ice from that glare.

"You don't have to change back, though, I think you're perfect the way you are," Yuu said, wrapping around Mika from behind again.

"What are you planning on doing?" Mika asked.

"Well," Yuu said. It sounded like he was pouting. "I was planning on playing with you for a bit, but you don't seem like you want to. Should I kill our new family instead Mika? Do you want another one dead?"

"No!" Mika shouted. Shit, he screwed up. He wouldn't exactly call Shinoa and the others family, but he did care about what happened to them and he wouldn't let a comrade die again.

"No, I'll do what you want." Mika said hurriedly.

"Really?" Yuu sounded so happy and surprised that Mika felt a bit sick. "That's good. Play with me, Mika~" Yuu let go of him and pulled him so they were both sitting down on the ground.

"Do you know any games?" Yuu asked.

Mika just stared at him.

"What? Why are you looking at me like that?" Yuu asked angrily, growling.

"You weren't joking, you meant real games?"

Yuu shrugged. "If you want to do something else that's fine with me. Only one of us might enjoy it though~." Yuu said before putting his hand on Mika's thigh. Mika scooted away from him a bit.

"No, let's play a game," Mika said.

"Okay, like what?"

"...Rock paper scissors?"

"You've got to be kidding me."

"It's not like the vampires played all sorts of games back in the sanguinem."

"Oh, I'm sure they did, just not the type we're talking about now."

They used to play games all the times with their family back when they were kids, Mika knew that. Somehow he'd forgotten most of them, or at least the ones Yuu seemed to enjoy. He didn't know how he could do that, but most of his memories back then were fading away. He couldn't dwell on that now though.

Yuu suddenly pouted.

"You've failed me, Mika. I'm too bored now, I can't help myself. I'm gonna do what I want."

"Wait, Yuu-chan-!"

"Oh!" Yuu suddenly clapped, looking as excited as if Mika just told him the war was over. Though, he probably wouldn't care in this state. "I have an idea!"

"What?" Mika asked worriedly.

"I thought of a game we could play. I'll go first." Yuu said, biting Mika's neck.

Mika didn't know what sort of game this way, but he didn't want to admit he was enjoying it. Now he knows how Yuu feels when Mika bites him, or maybe not. Maybe he only felt this because of how he felt for Yuu, but this was so incredible.

"Mika~ you're not paying attention to me. Why didn't you hold me like I hold you when you drink my blood? Am I not cute enough?"

"Cute enough?" Mika asked perplexed.

Now he was just messing with his head.

Yuu nodded frantically. "I think you're really cute when you drink my blood."

Mika felt his face heat up. "You're joking."

Yuu smirked. "Not at all~"

Mika couldn't tell what was the truth anymore.

"Now it's your turn, drink my blood, Mika!" Yuu said like some sort excited small puppy. It was sort cute if he was being honest.

He wasn't sure if he should do this, but he had to do something to keep the demon busy.

He bit Yuu's neck, and Yuu wrapped his arms around him and stroked his hair like he wasn't a demon right now.

When Mika finished, Yuu licked the remaining blood off of his face. He really reminded him of a puppy now. Or a murderous dog disguised as a puppy. Was the blood loss getting to Mika?

"You're kind of messy, it's cute, though." Yuu smiled at Mika.

"Is there another part to this game?" Mika asked.

"No, not really. I really want to kill them, Mika." Yuu said, smiling as if he were talking about anything other than that.

"Yuu-chan..." Mika tried to think something to do or say, something to stop him.

"You can't kill them." He finally said.

"Why not? I can, you and I both know it."

"I...I don't want you to." Mika had no idea why he said that, it's not as if the demon would care about what he wanted.

"Really? Why didn't you just say so?"

"What?"

The demon snorted. "You think if you say you don't want me to, I won't? How pathetic."

Mika didn't know what to do, he'd have to try to physically stop Yuu-chan somehow, but Yuu-chan was much stronger in this form. Most likely stronger than Mika.

"However, I'll play along with you this time. I won't kill them, happy?"

"What?" Mika asked dumbly.

"I won't kill them. For you, of course. You owe me a favor, though, keep that in mind." The demon said before Mika was greeted with emerald eyes once again.