If Rin were anything but half-demon, he was sure he wouldn't be able to force himself to stay awake nearly as long as he did.

But he couldn't force himself to sleep either. While Yukio was neglecting Rin in favor of doing literally anything else, Rin had somehow developed some not-so-great habits. One of them was staying awake for days at a time. He'd been having nightmares since Satan had possessed Shiro and they'd only gotten worse as the year went on and more things happened. The suspicious amount of sleep he'd been getting before(11 hours, wow) was a result of Rin adapting to being unsealed. Then he just got the regular seven to eight hours of sleep for a while. And now he got nearly none. Was this how Mephisto felt, always being awake? Surely his host had to rest at some point, though.

There was a good reason behind the sleep deprivation, though, so Rin felt no remorse for depriving himself of said sleep. Recently, the nightmares had changed. Instead of just reliving the things that haunted him constantly, Rin was faced with dreams of Satan possessing his friends and trying to convince him to come home as their bodies slowly fell apart, combusting from the inside and covering Rin in blood and chunks of person whenever Satan got close. Satan wanted him to come claim his crown and rule with him. To come say hello to his dead mother's soul that Satan held onto for some reason. Or maybe it was just an illusion. Rin would never know because he would never side with Satan.

He always wanted Rin to go to Gehenna and be with his people. While the idea didn't sound half bad, there was the small matter of Satan still being stronger than him. Satan would overpower him and use his body to terrorize everything Rin loved in Assiah before it combusted.

So, in order to not have to see the dreams anymore, Rin forced himself to stay awake and he didn't suffer the reprocussions humans did until the last few hours before his body made him sleep. It at least gave him more time to do homework and study for school so he could pass.

Rin knew he had a lot of insecurities. If Satan ever found them during any of those dreams, he'd rip Rin to pieces and have a chance at possessing Rin where he was in Assiah. If Rin's body was strong enough, he'd destroy everything Rin cared about. If Rin's body wasn't strong enough, his life and achievements would amount to nothing and Rin would die an incredibly pitiful death and his possessed body would destroy as much of humanity as possible before turning to mush.

Tonight was turning out to be different from his usual hours of schoolwork though. He was startled by Amaimon suddenly staring at him through the window in front of his desk as he'd been staring off into space and absently tugging on his new ear piercings. He'd missed having them. He had four in each ear and one in his tongue (Mephisto had consented to him getting all the piercings he wanted since he was Rin's legal guardian). His left ear had a lobe, upper lobe, a helix, and a daith. His right had a lobe, an upper lobe, an orbital, and a rook.

Amaimon had made sure Rin knew just how much he was loving the piercings. Between classes and all throughout lunch, he'd pulled Rin into corners or behind bushes or up in trees to make out messily and leave marks on each other until something called their attention away. Thankfully, Rin's hair was always naturally messy anyways, so no one inquired about sex hair, at least.

The aforementioned Earth King was now outside Rin's bedroom window. On the third floor. The demon tapped his claws on the glass and Rin debated letting him in for a moment before sighing and opening the window. The Earth King entered the Dorm and sat on Rin's desk in front of him.

"Did you need something?" Rin asked.

"I got bored. I thought humans slept at night?" Amaimon answered.

Rin shrugged a shoulder. "Most do. Not all of us." He said.

"Hm. But you slept the last time I saw you?" Amaimon pointed out.

"Yeah. Humans can't just permanantly go without sleep. They have to crash once in a while. Being half-demon lets me stay up for a pretty long time before then, but I still need sleep to function after avoiding it for a while." Rin explained.

Amaimon pulled Rin closer and Rin felt his Lizard-like tail wrap around his waist before he was lifted up by the appendage and placed in Amaimon's lap, straddling him on the desk. Amaimon placed kisses on his neck and Rin frowned. "I'm not your personal toy." He growled. Being used was not part of his morals! He liked the attention, but that was all it had been lately. Physical attention. No more compliments, no more assurances that he was worth it. That hurt him more than he cared to admit.

Amaimon bit him in response and he winced. "Never, you're much more than that, Prince. But if you're going to be up all night, you might as well do something fun instead of doing what the humans told you to. I'm bored and so are you and we're the only ones up. Mephisto has to sleep tonight because his host will fail him if he doesn't." Amaimon nipped at the daith piercing in Rin's ear and the teen shivered.

"And what about your host?" Rin asked.

"I slept the last time you did. That was sufficient enough for me." The Earth King said, tangling a clawed hand in Rin's hair and pulling him down. "Unless I expend more energy."

Amaimon's long tongue invaded his mouth and Rin fell into the kiss easily now that he knew he wasn't just being used. This kiss was different than the heated make out sessions Amaimon had initiated all week. This one was slow and languid. Amaimon took his time to enjoy kissing Rin. There it was. The affection that came off Amaimon when he wasn't rushing to get off or hurriedly satisfying his need to be around Rin all the time. There was the want Rin needed.

Rin still didn't understand why the Earth King really cared that much about him in particular, but Amaimon seemed to at least enjoy his presence and asking him about various human customs and emotions sometimes. Rin was patient with Amaimon and the Demon King seemed to appreciate that. Rin guessed that when you were an all-powerful, several thousand year old Demon King, everyone expected you to already know everything and didn't bother with details like Rin did. Thankfully, Rin was used to over-explaining things to Shiemi, so he had no problem doing it with Amaimon.

The Earth King reached around and ran his claws along the fur of Rin's tail. Shudders erupted across his body. "It feels good if you go with the fur, but when you go against, it's so much better." Amaimon breathed, stroking the tail the opposite way. Rin let out a surprised moan. Amaimon stroked the base of the tail where skin met fur and Rin clung onto him tighter. So many nerve endings in one place....He shuddered in want.

Amaimon's tail came up to prod at Rin's lips and he opened his mouth reflexively. The long, smooth scaled appendage slid in, farther and farther, until it was about halfway down his throat. Rin moaned around it and Amaimon shivered.

"Mn, you really let me put it in that far. It doesn't hurt you?" Amaimon crooned, putting a hand around Rin's throat and squeezing just enough to feel where his tail stretched Rin's esophagus. Rin released a wanton sound and instinctively swallowed around the appendage, his throat constricting around it impossibly tight for a moment. Amaimon let out a strained moan at the sensation.

He trailed his claws along Rin's tail at the base and the teen bucked his hips, moaning around the tail in his mouth. Amaimon pulled the tail out slowly, watching as it slid out of that hot, tight throat. The Earth King dived in to initiate another kiss as soon as that mouth was free. Rin's hips rocked against Amaimon's in little bucks and the demon purred at the feeling.

He twined his tail with Rin's and then started moving them together, sending jolts of pleasure through both of them. Rin keened into the kiss, wrapping his arms around Amaimon's neck to hang onto him. His body felt like it was turning to jelly the more those smooth scales slid against his tail and pushed the fur the wrong way just right. The Earth King grabbed the boy's hips and pulled them doan to meet his as he rocked up. They moved together on the sturdy desk, moaning and whining and purring.

"Amaimon, Amaimon, please~!" Rin pleaded, tail writhing against Amaimon's, body shuddering in the Earth King's lap.

Amaimon directed their tails to his mouth and bit down on both of them lightly. Rin cried out and came loudly, arching against the Demon King. Amaimon groaned and came as well, hands holding Rin's hips tighter and probably leaving bruises. He nibbled on the tails a little more and Rin held onto him for dear life as he finally finished his drawn-out orgasm.

They sat panting against each other for a moment before Amaimon picked Rin up, slid off the desk, and carried Rin to the bathroom he remembered using days ago. They proceeded to have even more fun in the bath because Amaimon just loved Rin's piercings and they both had amazing stamina. For the next two hours, they were a mess of writhing bodies in hot bubbly water. The heat Rin pit off when he was turned on kept the water nice and hot the whole time, too. The last thing Rin remembered was Amaimon tugging on on the helix piercing in his left ear and ramming three fingers into his prostate and the half-demon came so hard he blacked out.

When he came to again, Amaimon was cuddling with him in his bed. "You need to sleep or your flames will get out of control as soon as you get frustrated." The Demon King murmured to him, spooning him from behind.

Rin turned around and tucked himself against Amaimon's front, tangling their legs and tucking his head under Amaimon's chin. Hopefully, his nightmares would leave him be after exhausting himself.

§~•~§~•~§

They ended up sleeping in late and Rin complained about it, but Amaimon suggested saying he needed a mental health break if anyone asked the next day. Rin figured that the normal school system would call bullshit, but decided that would be sufficient since he was involved with Mephisto.

They cuddled and made food all day. Well, Rin showed Amaimon how to make simple things with the Demon practically clinging onto him the whole time and then Amaimon had Rin sit on his lap while he fed him after, curling his tail possessively around Rin's ankle.

"Is this like that thing about wolves? They like it when their mate eats their food cuz it means they're healthy and strong?" Rin turned to look at the Earth King.

"Something like that." Amaimon affirmed. "But with demons, it's more like we want the people we favor to take our possessions so they'll have something with them that claims them as ours until a contract is made, a courtship is initiated, or that person is exiled from the Demon's life. It differs depending on what happens between them."

Rin hummed thoughtfully. "So what happens if they start courting? Humans did that a really long time ago, back when there were still Monarchies and Nobles." He recalled.

"Are you sure you needed your friends to pass school?" Amaimon wondered.

Rin laughed. "Yes, because Math and Science kick my ass. English, History, and PE are the easier ones. I actually learned English as a kid because people used to donate their kids' old stuff to the Monastery, including Disney Movies, records, CDs, and plenty of iconic American pop culture films and some odd seasons of shows. I watched them a lot. And I like American pop music too." He recalled. "History is entertaining because you learn about centuries and centuries of people making the same mistakes and not learning, so it's just associating terrible country leaders to other terrible country leaders. Monarchies, Poverty, Corrupted Governments, Backstabbing, Spies, Revolutions, Advanced Weapons–It's all just a chaotic mess no matter what page you flip to in the history textbooks. And I might as well be the King of chaotic messes." Rin explained.

"Ah. That does sound entertaining. But, courting is something Demons still do because it still works for us. Courting is where one demon asks the person they wish to marry to let the Demon woo them." Amaimon said. "If the answer is yes, the demon who initiated the courtship will give the other gifts. If the recipient is pleased with the gifts, and by extension, how well their partner-to-be knows them and what they enjoy, and finds that they do want to spend the rest of their life with the other, then they will say yes when the other asks to marry them. When they get married, there is a ceremony held and when the marriage is consummated, their powers will be combined and they will be stronger, both individually and together." He fed Rin another Taiyaki as he explained.

"Woah, lucky! Humans just have a ceremony to say vows, get binded legally, someone changes their last name, and that's it unless one dies or they get divorced." Rin told him with a disappointed sigh.

Amaimon huffed out an amused laugh. "Humans aren't very efficient beings are they? They live short lives and unless they did something as drastic as ending a war or sacrificing themselves to save several other equally weak humans, they are completely forgotten eventually. Everything they build will eventually return to dust and they'll start new once more. Humans want to advance in technology and never stop to realize that if they stayed how they were, this world wouldn't be falling apart. Once they realized they could, they never stopped to wonder if they should." The Demon King noted.

"God made humans so there would be beings with free will to willingly follow Him. He didn't like having to take away the Angels free will, but after Lucifer, He was forced to because He didn't want to banish any more of them. But, humans strayed from His path and keep doing it. At this point, I wish God would just redo Noah's flood and start over again." Rin recalled the story Shiro had explained to him.

"Oh? And why doesn't he? It would do humans a lot of good to be wiped out but for one family that has devoted themselves to Him." Amaimon asked curiously.

"The rainbow is a symbol of the promise God made to never flood humans again after Noah. Trust me, when I was younger and an even bigger outcast living in the shitty part of Tokyo, I asked my Dad why God wouldn't just kill us all again and start over. That story was the answer. It pissed me off, so I refused to sit through Sunday Service for a month." Rin snickered.

"Well, at least the Fake Priest knew his Bible stories." Amaimon muttered. He ate more soba and fed Rin some more. When they were finally full and there was still more food left, they packed it up in containers and went to Faust Manor to gift the food to Mephisto.