Haru is a sex monster and Rin finds this out all too suddenly.

When they first fuck, Haru tears the condom off Rin's cock and forces him inside, sucking him in with no warning whatsoever. He flips them so Rin is on top and grabs him, violently thrusting them together. He starts a rhythm quick enough to catch Rin off guard, but Rin takes control again and the friction becomes explosive. They ejaculate prematurely, but there's no time to be embarrassed because Haru practically mewls in his ear to rough him up again. The cycle restarts.

Rin is perfectly capable of fucking Haru's brains out. He knows this from experience.

The only thing he fears for is his stamina. Haru is absolutely insatiable, moaning for Rin to fill him up to the brim, come in him over and over until they're both so dehydrated they're forced to take a break. This happens on more than one occasion. Rin's almost sure Haru has no refractory period.

Blowjobs with him are far from simple. Haru makes him come multiple times, into his open, waiting mouth. Once down his throat, twice in his face. Haru looks up at him with these shining eyes, lips red and coated with his essence, and Rin finds it impossible to deny him of this pleasure. If Rin's not plowing his ass, he's plunging into Haru's mouth or Haru's hand or Haru's thighs, a slave to Haru's unforgiving needs. Haru never lets him come only once. He seems to make it a goal to suck him totally dry.

"Are you a fucking demon? A literal fucking demon."

Rin slams into him against the wall. He'll derive as much as he can from this position before Haru motions him toward the bed. After all, carpet stains are hard to remove. Sheets are much easier to wash.

Haru sort-of-sighs. It's more like he wanted to sigh but halfway out his throat it became a wail. Probably because Rin hit something inside at the perfect angle to make his toes curl.

"You've asked that before, idiot. Shit, don't you dare slow down." His breath hitches as Rin finally falls into a delicious rhythm of merciless thrusts.

They're both close, so Rin brings him to bed, still sheathed in his impossibly tight heat. He pulls out slowly, listening for Haru's low groan, only to enter him again. And again, and again.

"You cumslut, tell me where you want it. Beg for it."

Rin drinks in his whines of impatience. Haru chokes on his own breath.

"I want it inside Rin, please, please."

He gives it to him and Haru twists and tears up from sensation overload. But he whines when Rin pulls out. It's not enough, it will never be enough.

"Again, do me again, or I will kill you."

"...You ARE a demon."

Haru pants harsh breaths into Rin's neck, whispering colorful expletives and threats that would make mothers everywhere faint.

"How are you not tired, we've orgasmed like twenty times."

"You've only come four times, stop complaining or I'll make you wish you came twenty times."

Rin swallows down his pride and Haru rewards him with a kiss.

"Have you passed out yet." Rin is holding him up by the waist. Haru's legs are shaking like a newborn deer's, but he's still going strong. Sweat and spunk drip down his inner thighs and it shouldn't turn on Rin as much as it does.

"I could ask you the same thing. Your performance has been going downhill since we started."

"Oh, fuck you."

"That's the plan, Rin." Haru moves his hips to meet his thrust, aiming for his abused prostate.

The sheets are a mess beyond recognition. Haru collapses when Rin finally lets go of his hold around his middle. He moans quietly as come drips out of his hole, clenching muscles to keep it in, but to no avail.

"I'm getting water. This is ridiculous." He turns back to check on Haru, but he's met with a heated glare and the blue-eyed demon sucking on cum-slicked fingers.

He throws his arms up in frustration and leaves the room.

Rin nearly drops his glass.

In the few moments he was gone, Haru decides to tease him a little more. Semen is spread all over his chest and stomach. His legs are splayed invitingly open as Rin's come leaks out of him.

"Mmm, welcome back. You took a while."

"I was only gone for two minutes! Are you fucking serious." He hands his glass to Haru, who drinks it rather greedily.

"I already miss your cock inside me. I need you in me again." He trails saliva-wet fingers up Rin's spine, licking his sweat stained skin.

"What the fuck. Don't say that with a straight face, it's creepy. And no, I'm exhausted. You have a serious addiction."

Haru crawls into his lap and grabs his dick, giving it a long stroke.

"…Goddamn it Haru."

Haru cries out in near agony, release denied at a single point. Rin fucks him hard enough to bruise and Haru hates and loves him all at once.

"Are you satisfied yet? I bet I'm fucking you so hard my dick is leaving its imprint in your ass." Haru squirms in his hold. He can't stand it, he needs this so badly but Rin's grasp around his dick restricts him to a whimpering mess.

"I'm not letting you come until I'm done, okay?"

He traces Haru's jaw with a wandering tongue. Haru fucks himself back on his cock, trying to milk the orgasm out of him. Rin laughs sadistically when Haru's body quivers futilely.

"Come on Rin, come inside, let me come."

Haru becomes a gibbering mess, tongue heavy in his mouth. Exhaustion has finally caught up to him.

"Heh, cute. Okay, I'll let go. Are you ready?"

Rin pistons in and out of him relentlessly, matching the rhythm of his strokes to the onslaught of pressure on Haru's prostate. Haru bawls and his body racks in pained pleasure as his orgasm hits him like a freight train. He tightens around Rin, twitching, pulling him down the edge with him into ecstasy.

"I can't move at all. This is all your fault."


"Ugh, I can't even get up to help you wash off. It's … all over you."


"I'm not having sex with you for a whole month. That was just too much."

Haru has the gall to look insulted. He shuffles close to Rin, burying his face into the crook of his neck and mumbling.

"I feel so full. It feels good when you come inside." Rin chokes.

"Shut up. Go to sleep."

Even if he is demon spawn, Rin holds him close. A content, love-filled Haru means a happy Rin and the universe aligns itself right again.