A/N: I'm actually fairly fond of this fic... It's surprisingly well-written. That's not going to happen again. Anyway, I like this pairing. Both of the characters are far too amusing. As is Hibird. Anyway, BL warning, of course.

Litmus Test

A lot had happened in the past two years of Hibari Kyouya's life. When before he had stalked the halls of Nanimori, itching for someone with the teeth for it to step up and challenge him, bored out of his mind, honestly, now even a moment's peace was rare in between fighting and meddling and extraordinary exercises of Hibari's restraint. A stolen moment on the rooftop where absolutely no one knew where he was had gained a spice of excitement. He was never sure what his next move would be—would he run away from all of this and continue this moment forever? Or would he come back down eventually, for the sake of blood, both spilled and intermingled in his veins?

Hibari exhaled slowly, dizzy with the heat of the sunlight pooled all over him. His arms were folded behind him and he was stretched out on the rooftop, cooking slowly. He figured he had about four more minutes before the warmth lulled him to sleep. Hibird had nestled into the crook of one of his arms, drowsing as well. The sound of Nanimori—all of Nanimori—had drifted into white noise and Hibari's eyelids drooped.

He didn't bother to open them when he heard footsteps from—one, no, two—flights of stairs down. There was no threat to perceive. He lazily guessed at the intruder's identity at its approach. A few feet away from the door the intruder tripped, banging into the railing loudly and letting out a string of curses, and Hibari promptly knew the man's identity. He tried to force himself to sleep in time, but that only woke him up more and when a shadow dropped over him, cutting out the baking sunlight, Hibari's eyes were open and glaring.

"Hello, Kyouya!" Dino said happily. Hibari sighed.

"…Hello."

That being all the invitation Dino required, Hibari suddenly found Dino flopped next to him on his roof. That stupid jacket hit him in the face. Hibari's fingers itched to kill something, but his body was too sluggish to reach for his tonfas. Well, a few second's conversation with Dino would probably solve that problem.

"It's always so nice up here," Dino declared, also folding his arms behind his head. He appeared to be staring at the sun. Dino's clumsiness didn't really need the added help of him becoming blind. Besides, if Dino failed to prove an adequate sparring partner because of his own stupidity, Hibari would feel fully justified in biting him to death. He turned his head to glare at Dino, who smiled back at him (at least he wasn't staring at the sun anymore). "You still come up here a lot, don't you, Kyouya?"

Again with the first name thing. Hibari regretted having given him permission. Sort of. Dino had never asked and Kyouya had never said anything pleasant that wasn't by omission.

"Kyouya is a nice name," Dino declared during their third day of beating the living daylights out of each other because Dino was both interesting and desperate. "I'm going to start calling you that." He made sure that Hibari understood, perhaps feeling that middle schoolers were too stupid to understand Japanese by adding, looking Hibari dead in the face, "Kyouya."

Hibari, who was currently too tired to really do anything about his self-proclaimed teacher's breaching the code of conduct Hibari lived by and also unsure as to whether he could, at this stage, dole out an appropriate punishment, glared and said, "You're my opponent, so shut up. Get your breathing under control. I want to fight."

Hibari didn't know why he hadn't withdrawn his grudging permission by now. He was almost out of middle school and far stronger than before. He could, if not force Dino to submit to him, make Dino regret very much that he'd incurred Hibari's wrath.

"Kyouya?"

Hibari realized he was dozing off again, and blinked lethargically at Dino's affectionate smile. Dino laughed lightly. "Didn't you get enough sleep last night?"

"It's warm," Hibari answered lazily, that being enough of an answer for the time being. Hibird fussed at him a little bit for talking so much and Hibari quieted down again, listening to the sound of Dino's breathing mixing with his own. Everything was mixed these days. Herbivore and carnivore. Enemy and ally. Distance and…

"I don't think I've ever seen you so relaxed," Dino remarked, breaking the peace again with his carefully articulated Japanese. "You haven't swung a tonfa at my head even once."

Hibari cracked an eye open with a threatening smile. "Would you like for me to?" But Hibird fussed again and Hibari couldn't really get his muscles to solidify. They seemed to have melted, along with the rest of the world that wasn't the Nanimori school building's rooftop and the way sunlight glared off of Dino's blonde hair.

"No, I'm enjoying this far too much," Dino replied happily, drawing a resigned sigh from Hibari. He could feel Dino looking at him, but it wasn't as unsettling as some. Hibari was used to Dino always looking at him anyway, correcting, applauding, paying attention… He was his mentor, after all. Hibari had acknowledged that, and planned to correct the hierarchy back into its proper order as soon as he surpassed his teacher. He had no plans to dismiss Dino when he finally defeated him. He could not, after all, permit the loss of his best sparring partner to something as insignificant as Dino being lazy.

Dino laughed again, drawing Hibari's mind back out of its haze, and although Hibari didn't bother looking over at him, he could hear it whispered clearly. "Geez, Kyouya, you really are cute."

"Shut up," Hibari commanded imperiously, landing what passed for, from him anyway, as a light kick on Dino's shin. Dino whimpered like a child. "Stupid pedophile."

"So now I'm a pedophile, just because I think my student acting his age is cute?" Dino demanded, irritating Hibari who was ready for Dino to shut up so he could go ahead and go to sleep. And there was nothing 'cute' about Hibari taking a nap. He was just taking a nap. That was it. And while he was on the subject, Dino was being patronizing, which made Hibari want to hurt him. "What is this world coming to?"

"No," Hibari explained, opening his eyes again to cut into Dino with them. "You're a pedophile because you're a pedophile. Saying vulgar things about my sleeping habits is just a result." Dino pouted in a way that no grown man should ever do. Hibari got tired of looking at him.

"But how was that vulgar?" Dino wondered aloud, whining.

"You know perfectly well how," Hibari said, although he personally didn't. He was sure Dino's overactive imagination could come up with something far worse than anything his sleep-muddled brain could suggest. "I advise you to seek professional medical help. You may have childhood trauma that you need to work through."

Dino said nothing. Hibari was sure he was pouting again, and didn't care. People did not seek out Hibari Kyouya for the warm fuzzies. Dino was lucky he wasn't bleeding yet. Though there was time to correct that… Hibari's darker train of thought derailed slowly as the sun sank into his skin again, and Hibari could feel himself just melting to the bone. It was so hot today. He was probably getting dehydrated.

"You know what?" Dino said suddenly, loud voice ruining Hibari's peace once more. Hibari did not know what, nor did he wish to. Dino knew this, and continued to talk in his loud, irritating voice anyway. "I don't care. You're cute, Kyouya, and that's just how it is. And I like seeing you this way. And I'm not going to just pretend—"

Hibari sat up sharply, sending a startled Hibird fluttering into his hair. The look he gave Dino was nothing short of murderous. "Since you are incapable of being quiet," he growled, clambering gracelessly to his feet and trying to ignore the sun's rays dragging him back down. "I am going to go find somewhere else and I am actually going to go to sleep there. If you follow me, I will bite you to death, and if I happen to fail somehow, I will continue to pursue you and personally tear you to shreds."

"How is that any different from now?" Dino grumbled, and when Hibari failed to respond (mostly because it was true), Dino stood up as well, hands shoved in his pockets. "Look, you don't have to leave. I'll go. Just… take back what you said, OK?"

"What?" Hibari snapped, temper rising because he was tired and dammit, Dino just wouldn't leave! And if he made Hibari fight, then he wouldn't be able to get back to sleep for a few hours, which meant someone would find him, which meant he would be even more sleep deprived than he already was, and if that happened, Hibari would probably end up killing the next three people he saw regardless of what punishments were actually appropriate, which was truly unbecoming of the leader of the Disciplinary Committee.

Dino shrugged uncomfortably, not really meeting his eyes. "That… pedophile thing." Hibari's eyebrows rose and Dino looked at him unhappily. "I mean, that's not really what you think, is it?" And then, under Hibari's mostly incredulous gaze, Dino turned his eyes back to the rooftop under their feet, fidgeting like a child being scolded. It took a moment for him to believe it, but when he did, Hibari blinked. What he'd said had actually bothered Dino. He hadn't known that was possible. The man had no pride whatsoever.

"Kyouya," Dino sighed, exasperated, looking annoyed now. "You want me to leave right? So, say something!"

Hibari blinked again, and then smirked. He took a step closer to Dino, placed both hands on his shoulders, and stared up at him as earnestly as he could manage. Dino's eyes had gotten very wide indeed and he stumbled back a step, Hibari following him effortlessly and continuing to gaze at Dino's increasingly nervous face. Dino was choking on his words, spouting out little pieces of broken Japanese before he finally seized Hibari's own shoulders to keep him from invading his personal space, and really, this was far, far too easy. Dino discovered he had been maneuvered neatly against the railing as Hibari leaned in slowly, watching the dawning horror on Dino's face with glee and snickering privately at all the garbled Japanese. When Dino finally did say something it was a string of breathless, unintelligible syllables that Kyoya instantly knew to be Italian. It sounded like a prayer.

Hibari silenced it with a kiss.

Although Hibari had never found himself interested in his own species for anything more than fighting, it wasn't like the mechanics of a kiss were beyond him. By Dino's standards it was probably a laughably childish kiss, but Dino was a bit preoccupied at the moment with the knowledge that his far younger, very male, and potentially deadly student was kissing him. Hibari kept his lips against Dino's warm, soft ones, and after what he deemed a suitably embarrassing amount of time during which Dino stood frozen like a statue, Hibari leaned back, smug and pleased to find that Dino's face was bright, flaming red.

"Did you enjoy that?" Hibari purred, narrowing his eyes and watching Dino gulp in panic. Hibari leaned close again and was immensely amused when Dino actually flinched away. "If you did," Hibari whispered in his ear, feeling a shiver run through the shoulders he was still resting his hands on. "…Then that means that you're a pedophile."

Dino abruptly released Hibari, who held his ground trying not to laugh at the affronted look he was getting. "If you enjoyed that," Dino said bitterly (and still bright red, Hibari noted), "Then you're a sadist."

"Oh?" Hibari replied, raising his eyebrow as he stepped away from Dino. He stretched in the sunlight as Dino started for the door, muttering under his breath about how generally annoying Hibari was. Hibari couldn't resist glancing over his shoulder at Dino and asking mockingly, "I wonder if we shouldn't test to see if I'm a sadist as well…?"

Dino fled.

Hibari settled back down onto the roof, making up with Hibird as he listened to Dino tripping down the stairs as he practically ran from the rooftop. He laughed quietly, a secret between him and his feathered companion, and at the very least, Dino was not there to call him cute.

Dino's reaction had been quite amusing. Hibari would have to try it again sometime.

But first… peace had returned, and Hibari allowed himself a moment longer in the heady sunshine.

"Dammit," Dino growled from the back seat of the car, breathing far more heavily than he really should be after such a short run. His heart was hammering. He could have strangled Hibari, he really could have. "This sucks!"

"I thought you'd be happy, boss," Romario said, glancing back at the Cavallone boss, who had both hands plastered over his face in an attempt to hide the remarkable color it had taken on. It was a childish gesture, and Romario was doing his best not to smile because he knew his boss wouldn't appreciate it. "It seems that your feelings are reciprocated."

"Reciprocated? That?" Dino laughed with an edge of hysteria. "That was not reciprocation. That was the sealing of my doom. I am officially a dead man. Kyouya knows. There's no way he missed that. Oh crap, oh crap…"

"Hang in there boss," Romario patted his shoulder sympathetically before starting up the vehicle. "At least you can't really call it pedophilia when you're more immature than he is."

Dino wailed, slumping into the car seat. "Don't put it like that!"

And on the rooftop, fast asleep, Hibari dreamed of sunlight and a flowing Italian voice that wove into his breathing.