Disclaimer: I own nothing

Pairings/Warnings: RinHaru, m/m sexual content, biting kink, some sapness

A/N: Written some time ago... (more of my AO3 cross-posting)

Bite Marks

The moan that Haru made was low, sensual, quiet but loud seeming in the quiet of Rin's dorm. He was biting his lip when Rin looked up, trying not to be too loud as Nitori was asleep above, the sound of his heavy breathing and light snoring heard above their activities. Perhaps they should've been more discreet, gone somewhere else but when Haru had turned up when Rin was out for his jog and they'd "bumped" into each other, well, he wasn't going to turn him away. Nitori was a heavy sleeper so Rin didn't give a shit. Plus Haru was pretty quiet.

Or he usually was. Except for right now. Maybe it was because Rin was licking at his thighs, mouthing the pale skin, his eyes looking up to see Haru's expressions shift and change, his neck arc backwards and hair spill over his eyes. He looked so damn good like that and Rin bit down on the skin, hearing Haru's gasp of pain/pleasure.

"Rin… only there…"

Rin smirked. "I know, babe… don't want everyone knowing."

It tasted good to lick and mouth at the skin, to pull it up between his lips and know he was leaving marks and bruises. "Only there" was Haru's rule as if Rin bit down anywhere else it would be too obvious and he didn't want Nagisa or Makoto or Rei to ask why he was covered with hickeys.

As this was for Rin. Only for him. Only between them.

The first time Rin had bit down on Haru's skin had been during wild sex, Haru pinned against a wall, their jammers bunched around their thighs. Haru had been bucking back into Rin's body, panting, his arms trembling against the lockers, Rin holding him tight around his chest to keep him upright as he slammed his hips into Haru, his cock deep inside him, each push in and thrust out electric, and the sound of slick sweaty flesh slapping together heard above their gasped pants and moans.

It was when Rin was close, his body over-sensitised, his hand jerking off Haru and feeling him clench and twist and moan, that Rin had felt his own body reach the precipice, his dick twitching and he'd leant over and bit at Haru's shoulder, his teeth making an impression in the skin, Rin even tasting the coppery tang of blood on his tongue. The smell of Haru's skin, the lingering tang of pool water and the feel of Haru's body against his, and the feel of marking Haru, claiming him, possessing him – all made Rin come hard, an orgasm high like never before, his body weak and weary against Haru's.

Every time since then – every quick fuck, every slow sensual screw, every time Rin blew Haru or they exchanged hand jobs – one thing that Rin always did was bite at some point during their session, the noise that Haru made making his cock so hard and the feel of possessing him being one that turned Rin on so much that when they were apart, he would jerk off imagining that moment and the way Haru would look in ecstasy.

Like he looked now. He hadn't bit down hard enough for blood as he knew that was for only when he lost control, as Rin sometimes did, and this was more about the tease. He licked at his mark, lapping around the skin and eyed Haru's cock, pre-cum glistening from the tip and he gave Haru some reprieve, moving his mouth to lick around the head, his tongue in the slit and his eyes watching Haru closely.

"Rin – shit -!" he murmured and Rin stopped for a moment as the words seemed to rouse Nitori briefly, there was the noise of the bunk above creaking, the noise of him mumbling something, sounded like "senpai" and then it stopped.

Haru's head shook, indicating for Rin to stop but Rin didn't feel like doing that. As Nitori was asleep and Rin didn't give a shit if he did wake up. He had Haru hot and hard and naked in his bunk – what more did he want? He would have the smell of him on his pillow, his sheets and Rin opened his mouth, bobbing his head down onto Haru's cock, tasting him, swallowing around him, feeling hands tighten in his hair.

His mouth worked at the dick in his mouth, using the hollow of his cheek, his tongue, lowering his head slowly to bring it up, feeling Haru slide between his lips and enjoying the feel of those fingers far too tight, pulling at him as he swallowed him deeply. Rin couldn't quite deep-throat but it was enough, the way Haru's body jerked up was proof that Rin was driving him crazy and he backed off, letting Haru's thrust his hips up, fucking his mouth.

Rin could figure that Haru was close, his hand was in his mouth, Haru biting down on it and his thighs tensed so he trailed his lips off Haru's cock, lapping around the head a few times before he replaced his mouth with his hand, jerking him off in a fast rhythm as he returned his lips to those perfect thighs, mouthed at a spot, drawing up the skin between his lips.

"Fuck!"

He smirked as he bit down as Haru had lost that control, that stoicism replaced by pants and a keening whine. Rin would mock him later for the way he moaned but right now all Rin cared about was bringing Haru off, feeling his cum between his fingers, licking it off his perfect abs. He groaned as tasted skin and chlorine, as his hand firmly tugged at Haru's dick, his own hand briefly going to his own cock, rubbing to relieve some of the pressure as he moved his mouth one more time, biting down again and Haru came undone.

The hand in his hair seemed like it was going to rip some out but Rin didn't care as he caressed the skin with his tongue for a moment before he looked to see Haru boneless, stickiness between his fingers and staining his stomach, his chest and Rin saw even near his neck.

"Enjoy that?" Rin teased, moving to lap at his stomach, tasting the saltiness, licking a long trail up Haru's perfect body.

"Rin," Haru said, in warning and Rin snorted as he pushed himself up so they were face to face.

"What? I love it… marking you, making you 'mine'."

To demonstrate, Rin disobeyed Haru, going then for collarbone, biting down lightly but enough to leave a mark and Haru glared when Rin looked back up.

"Oh come on, they know," Rin said as they had to.

There had been too many and Nagisa asked too many questions that Haru was too awkward to answer and Makoto had just looked shocked and Rei had wanted to analyse them or some shit but Haru shook his head.

"I hate you sometimes."

Rin groaned then as a hand was at his cock, the feel of Haru's fingers on his so damn good even through the material of his track pants and there was a moment of wrestling on the bed, a moment where knees knocked and heads clashed and they made enough noise to hear Nitori murmur "senpai" again, pausing then as Haru straddled Rin fully naked, those marks glistening on his thighs and collarbone.

"But you like me most of the time, right?" Rin teased, his arms folding behind his head as Haru looked at him with heated eyes.

And Haru leant down, running his teeth along Rin's throat, biting down there once as his hand reached for his cock, twitching in his pants from the pain/pleasure of the bite and with a low drawn out breath, he made a noise of appreciation.

"Shit… I know why you like it now."

Haru gave him no more opportunity for words, meeting his lips in a searing kiss, stroking his cock and making him come undone, biting down on Rin's shoulder when he was close, Rin coming hard with a breathless "Haru", his body trembling.

"Can you stay?" Rin asked sleepily after, knowing there was little room and it was forbidden and there was Nitori but Haru only nodded, sliding to lie on Rin's chest and as he was about to fall asleep, Rin's fingers brushed the bite marks on Haru's thighs, thinking about how those bite marks proved to the world in their own twisted way that they belonged together.