Happy birthday to Hibari Kyoya! This is my present to him, despite him being completely fictional~

I don't own KHR! In my head I do though. And it's wonderful. ^^

Adapting

The first time Hibari Kyoya woke up in the same bed as Rokudo Mukuro, he reacted purely on instinct and kneed him in the balls.

It wasn't intentional at all, as strange as that may have sounded when it concerned someone as violent as Hibari. It was just a simple knee jerk reflex reaction that any other person in his situation would have done. Probably. The facts were that he was waking up in a strange room with a strange person in a strange position (which, for the record, he refused to ever admit to), when the day before he was waking up perfectly alone. What else was he supposed to do? It wasn't like he had woken up with Mukuro before, so kicking him in the balls was the only logical thing to do. Then he remembered that oh yes, they were supposed to be waking up together.

In hindsight, it wasn't really the best way to start a new relationship.

For the two most dysfunctional people in the Vongola, adapting to being a couple was something of a challenge. The transition from 'die you bastard' to 'let's do angry dirty things to each other' to 'alright, maybe I kind of like you' was something that no one else in the family had gone through. After all, nobody had a relationship quite like the one Hibari and Mukuro had. Quite frankly, nobody really wanted one like theirs.

Both seemed to forget that they were indeed seeing each other romantically, and that they really weren't supposed to try and kill each other in the quickest and – often in Mukuro's case – most creepily elaborate way possible. Neither had any qualms over hitting, pummeling, breaking or stabbing each other, much to the confusion of everyone who knew of their relationship, and they certainly had no objection to putting each other into the hospital for a day or so. That was how it worked between them, funnily enough, so they didn't particularly care.

It didn't start like a typical relationship. Neither had really pursued the other to proclaim any love and the notion of 'courting' was both foreign and insane to the two of them. In fact, all that had happened was that they had mutually decided that hate sex was good sex, and good sex was a resounding thumbs up. That began their twisted little affair that somehow evolved into an actual but equally twisted relationship. Mukuro realized that he had been getting kicked out of Hibari's room less and less and Hibari had noticed that Mukuro was teasing him less sadistically and much more playfully. Almost like childish flirting.

Finally, they decided to bite the bullet and rearrange their agreement. Well, it was more like Hibari thinking he had come to terms with things and putting his foot down. He stormed up to Mukuro, grabbed his shirt collar and yanked him down so the taller man was eye level.

'If I ever see you with anyone else, herbivore, I'll bite you to death,' he had warned darkly, which turned out to be his own peculiar way of telling Mukuro he wanted to be exclusive. Strangely enough, this was before Hibari realized that he actually liked Mukuro.

Mukuro had smiled playfully at him, admittedly not expecting that at all (but certainly not letting his surprise show on his face). 'Kufufu, as you wish, Hibari Kyoya,' he chuckled in response.

And just like that, they were an 'item'. Inverted commas totally necessary.

All they had to do was get used to it.

Out of the two of them, Hibari was the first to get jealous. Once again, this was before he realized what he felt for the herbivorous illusionist. It was common knowledge that Mukuro was openly bisexual. As long as his partner wasn't too terrible looking, he could sleep with anyone, gender be damned. That was why whenever Hibari saw Mukuro with pretty much anyone that was passably good looking, there was always a twinge of something bitter within him.

Naturally, his ever-present Mukuro-denial didn't allow him to realize that this was jealousy. That, however, didn't stop him from pinning the bastard illusionist down and writing 'Property of Hibari Kyoya – touch him and die bitches' on his face in permanent marker. To him, it was a perfectly logical and ideal way to deal with that particular situation, since a lot more people were wary to go near Mukuro after that – the exception being Chrome, who Hibari had never really seen as a rival.

While Hibari had no problems with hitting stupid women (he never did confirm to all that chivalry shit that most men seemed to think was necessary) he couldn't actually find any of the girls that dared to flirt with his whatever Mukuro was to him – as he refused to use the words lover, partner or boyfriend. He supposed the permanent marker was the next best thing. Which it technically was, since the black writing stayed there for a good few weeks before it finally came off properly.

As for Mukuro, envy was unfamiliar to him. He had never really cared enough about a significant other to get jealous, so he was decidedly amused to see it happen with Hibari Kyoya. The Cloud Guardian was pretty and it seemed that Italians liked that – what with both Dino and Mukuro being interested in him. When they went to Italy for some Vongola event that Mukuro couldn't care less about, it just got worse. Mukuro knew very well that Hibari could take care of himself when it came to perverted Italians (naturally leaving his good self out of that generalization) but even he had his moments of completely justified, totally reasonable and maybe a little bit irrationally insane behavior.

The first time Mukuro got jealous, nobody could find the body.

Eventually, after all the murders and all the threats and all the branding (Hibari had once actually attempted to brand Mukuro with a heated up tonfa but the illusionist was having none of it) the two decided to come to a compromise. No more killing in Mukuro's case, and no more defacing Mukuro's body in attempts to mark him as his property in Hibari's. Instead they resorting to cheap glares, silent death threats and, on one occasion, growling.

'Well, if I can't kill people to make them keep their dirty hands off you, what can I do?' Mukuro had argued when Hibari finally told him to stop with the murder. He didn't actually care that Mukuro was killing, it was just that he was the one that had to do the paperwork involved.

'Ignore it, idiot,' snapped Hibari. 'It's not like I'm interested in any of those herbivores.'

Mukuro playfully rolled his eyes and tugged the front of his shirt down a little, where the top of the characters for 'MINE' were written in marker. 'Because you are so wonderful at ignoring things like that yourself,' he countered.

Hibari sneered and crossed his arms, fingers twitching a little for his tonfa. He decided to go for the mature route and ignore the bastard, settling for glaring darkly at him instead. Mukuro just laughed like the herbivore Hibari decided he was.

It was two months into their 'official' relationship that Hibari realized he actually liked Mukuro. He didn't go about it conventionally like any other man discovering that – instead deciding to go about it his own way. And his own way was to get rid of it. Hibari's theory was that if he punched Mukuro in the head enough times, it would get rid of these strange feelings and such. He was Hibari Kyoya. He wasn't supposed to have strange feelings for people – least of all Rokudo Mukuro. Because feelings...they were for girls. Despite his somewhat androgynous looks, Hibari Kyoya was no girl.

With Mukuro's reflexes, and Hibari's habit of becoming predictable in his attacks whenever he was confused, he was unable to land a hit on the pineapple headed bastard. Mukuro caught both of his fists and playfully pulled him into a hug, uncaring of all the people in the room, having a feeling he knew what Hibari was so annoyed about.

After that particular scene, pretty much everyone knew that Hibari and Mukuro were sort of dating – the kind of dating that involved biting to death and the occasional consensual rape – but nobody could get used to it. They were just too strange to be in a relationship. Mukuro was one step away from Tsuna having him sectioned and Hibari was Hibari! Everyone had thought he was asexual before the whole situation with Mukuro which, for the record, was a completely reasonable assumption when concerning Hibari Kyoya.

Tsuna may have had a slight aneurysm when he found out about them.

Soon, Hibari got used to liking Mukuro. Just because the illusionist made him feel good (both physically and, much to his reluctance to admit, emotionally) it didn't mean he had to treat him differently to everyone else. On the contrary actually. He treated Mukuro the same way he always treated him, only a little less hostile than before. At least now he didn't try to attack him every time he saw the walking pineapple.

Now, waking up in the same bed as Mukuro was a regular thing. There was no more ball kicking out of reflex – very much to Mukuro's relief – and now he barely ever kicked the illusionist out of his room anymore. In fact, it was stranger to Hibari when Mukuro wasn't in his bed now. He was just to used to it.

He glared at the pineapple bastard tiredly, wondering why he was so used to sleeping next to him. Sure, he could take naps in front of other people, but he couldn't actually properly sleep with others around. Apart from Mukuro evidently. Sneering, he sat up, pooling the sheets around his naked waist and looked for his underwear, trying to ignore the sleeping illusionist next to him.

When he spotted his underwear, he slipped out from under the sheets, only to be pulled back by an arm. 'Let go, idiot,' he glared as he was dragged back into the bed.

Mukuro chuckled, not opening his eyes, and locked his arm tighter around Hibari's waist. 'Go back to sleep,' he muttered. 'It's still early.'

'The hell it is,' Hibari yawned. 'Let me go.'

'You're no fun.'

Hibari glared at him and grabbed his underwear, tugging them on languidly before looking for the rest of his clothes. That night they had gone to Mukuro's room instead of Hibari's, which was a rarity since Hibari was much more comfortable in his own place. He had to admit though, he found sex much better in an actual bed rather than his usual futon.

'Kyoya,' hummed Mukuro, opening his eyes and squinting when Hibari yanked the curtains open, 'do you know what day is it?'

Buttoning his shirt, he looked at the illusionist. 'Saturday,' he replied.

Mukuro let out a laugh and sat up, cracking his neck a little. 'I didn't mean it like that,' he grinned as he ran a hand through his hair. 'You really don't know?'

Hibari rolled his eyes. 'I don't care,' he said, picking up his tie. 'I'm going. There's a meeting at nine. Don't be late, herbivore.'

The illusionist offered a smirk and Hibari sneered, tying his tie. They both knew full well that Mukuro wasn't going to make it to that meeting on time. He liked to bug Tsuna by deliberately doing things like that – just because he was an idiot. Well, that was Hibari's opinion anyway. He yawned again and looked around for his blazer.

He blinked when he felt arms encircle his waist. 'I need to go, Mukuro,' he glared, turning around in the embrace. 'Put some pants on.'

'What? And deprive you of this?' grinned Mukuro, pulling away to gesture to his naked body. Hibari rolled his eyes and Mukuro tugged him back, brushing their lips together. 'Happy birthday, Kyoya~'

Hibari blinked and dumbly allowed Mukuro to kiss him again. He had never really celebrated his birthday, so it was only natural that he would forget it. To him, it wasn't important. He really didn't care about it. Despite that, he kissed the illusionist back slowly.

'Do you really want to leave now?' tried Mukuro again, offering a grin. 'You're not fully dressed yet, after all.'

Glaring, Hibari deliberated for a moment. He was actually practically dressed already, missing only his blazer and his shoes. After a moment, he sighed and loosened his tie. 'Half an hour,' he muttered. 'That's all you're getting.'

Mukuro grinned and pushed him down on the bed with a chuckle.

Maybe, Hibari thought to himself as Mukuro pulled off the clothes he had just put back on, getting used to all this wasn't so bad after all.

I'm painfully aware of how rushed it is at the end, but I'm at work in half an hour and I wanted to post this fic before tomorrow. I didn't get chance to look it over again, so forgive any mistakes, if you would be so kind. I may check it when I have chance, but until then I hope you enjoyed it~! :D