Hello again peoples! Day two of Yullen week, and I feel like shit. I always get ill during holidays and stuff, so I'm just hoping that I'll be okay for Christmas. Maybe a review would make me feel better?

Explanation time - considering today's prompt, I thought that lots of people are going to go with the whole angsty thing. Which is great; I love angst. I just suck at writing it. So, I decided to go in the other direction and try to produce something lighthearted.

Day two, prompt two: Bittersweet

In his lifetime, the Bookman junior, currently known by his forty-ninth alias Lavi, had sampled many delicacies from countries all around the world; however, he had never found one quite as refreshingly perfect as a glass of Jerry's special, homemade iced lemonade. It was particularly wonderful, he found, when it was savoured on especially hot days such as the one he was currently suffering. It was perfect – the bite of the lemons beautifully complemented by the sweetness of the sugar, all held together by a squeeze of lime – Jerry's 'super secret special ingredient'.

Lavi smiled happily to himself, taking another sip as a distant part of his analytical mind registered the outbreak of yet another argument between Allen-chan and Yuu-chan. Something about Allen sitting too close to Kanda while they were eating; Lavi just smirked. Those two embodied the perfect blend of bitter and sweet.

The tension between the two of them was enough to drive anybody mad within seconds of entering their presence, but Lavi held firmly to the belief that he had been insane for a number of years; things were far more interesting that way.

"Shut up, moyashi!"

"Make me, baKanda!"

Such things were surprisingly common occurrences, and to the extent of Lavi's rather extensive knowledge, the two of them had managed to cause a number of breakdowns amongst the scientist and Finders with their constant bickering. As well as their near-constant fighting. And sparring (which was, in fact, Allen-and-Kanda-speak for 'attempting to kill one another without Central and – perhaps more terrifyingly – Komui breathing down our necks').

In fact, now that Lavi thought about it, those two spent an awful lot of time together.

Now that was just not right. For his two bestest buds to be hanging out without the awesomeness that was him. Then again, he was technically supposed to be in the library helping out Gramps, so maybe it was a good thing that he wasn't getting involved. In the middle of their fights was the most dangerous (and therefore most exciting, though many people thought Lavi crazy when he pointed it out) place to be – there was no such thing as the eye of the hurricane for those two.

"Geez you two, if there's that much unresolved sexual tension between you, surely you can find a more constructive use for it than fighting like a cat and dog?" He grumbled, just loud enough for the now-brawling pair to hear.

Both of them immediately turned the full force of their combined-Kanda-Allen-twin-glare-of-terror-inducing-evil on him. Used to it and no longer bothered by its paralysing effects, Lavi chuckled and rolled his eye, standing up to leave, completely oblivious to the furtive glances the two were exchanging.

Lavi sighed, picking up his glass to take with him – Jerry wouldn't mind, he was sure, and Gramps didn't care what he did as long as he got his work done. Idly, he stirred the drink with his straw, wondering how long Gramps would keep him cooped up in the library before he was allowed to go out again. However long it took, it would no doubt feel like forever; the stuff Gramps gave him to copy out and record was so dry it made the Sahara look like a swimming pool. Why couldn't he ever get the exciting stuff?

The library was dark and quiet when he got there; Lavi spent a few minutes wandering around and lighting the lanterns that were scattered about haphazardly. Taking a seat near the back in one of his favourite armchairs, Lavi carefully sorted through the stacks of documents, arranging them by year, month date and then alphabetically within that frame.

Grabbing the fountain pen that lay oh-so innocently on the table, Lavi began his wrist-breaking work.

Lavi wasn't quite sure what had woken him – maybe it was the smell of the ink that was smudged over the left half of his face (Gramps would kill him for that later and make him rewrite the records from scratch, no doubt) or perhaps it was the fact that his head had just dropped off of the thick book it had been resting on when he twitched in his sleep. The lamps had all burned out, throwing the room into darkness, so it may have been that. No matter the cause, however, Lavi was awake and that was that.

Then again, it could have been the rather sudden opening of the door and the hushed whispers that drifted past curious ears.

"Are you sure there's no one in here?" Asked a voice that Lavi quickly identified as Kanda's, and the Bookman apprentice frowned – why would Kanda, of all people, come to the library? And with someone else; everyone knew exactly how anti-social he was.

"The only people who ever come in here are Lavi and Bookman – Bookman's in the cafeteria, and Lavi was in here hours ago, so he'll be long finished by now."

Well, well. Little Allen was with Kanda on a shady escapade in the darkened library? Kanda wasn't complaining, nor did it sound as though they were at one another's throats again. Now this was something for the records.

Lavi's eye widened as he listened intently – there was the sound of heavy breathing every so often, the rustle of clothes and what sounded almost like... like two people kissing. No, that wasn't right, surely. There was no way Kanda and Allen would... would... Then again hadn't he himself said that the unresolved tension between them could be used more constructively? He just hadn't expected them to actually, really, seriously listen to him. They never normally did.

He could hear it when they broke apart, their breathing uneven. Lavi held his own breath, though he doubted they could hear him either way.

"About what Lavi said earlier... Do you think he knows?" Allen asked softly, and Lavi could just picture the expression on his face. He could almost hear the cogs turning in Kanda's head as he thought about the question.

"I doubt it. He would've confronted us by now. Even if he does know, it shouldn't matter – he's supposed to be unbiased, remember?" Kanda said, his voice surprisingly soft and... calm. It wasn't a tone Lavi had ever heard from the other boy – he wondered briefly if it was a tone that Kanda reserved specially for Allen, to comfort the younger boy. The conversation was so far removed from their vicious fights and arguments that Lavi began to wonder if he was still asleep and dreaming – or, at least, if he was hearing things.

Lavi tried to block out the soft moans from the other side of the room and he had to bite his lip against a relieved sigh when Kanda finally muttered something about going to his room. Waiting silently until the door swung shut and he could no longer hear their hurried footsteps, Lavi let out a great shuddering breath and scrubbed at his eye with his fists before a wicked grin spread slowly over his face.

Kanda and Allen, hm?

The next day, Lavi waited patiently in the cafeteria at lunchtime, waiting for the arrival of his two bestest buddies. They had been 'training' (though Lavi had his suspicions about what had really occurred – no one dared interrupt those two anymore, so it was the perfect cover story, right?) so they would have to come by and refuel sometime, surely? He stirred his lemonade thoughtfully as he waited for the two.

Eventually they arrived, flushed and in total disarray; Lavi wondered how his keen bookman senses had never picked up on all of the subtle clues before. They had all been there – it seemed that everyone at the Black Order (including himself) were quite blind.

They sat down opposite him – Kanda with his soba and Allen with twenty or so plates stacked high with food.

"Say Allen, that's a pretty nasty bruise on your neck; how'd ya get that?" Lavi asked casually, indicating what was quite clearly a bite mark on the side of Allen's neck; his high collar didn't manage to hide it from Lavi's keen eye. Allen shifted uneasily, a slightly nervous smile spreading across his face whilst Kanda stiffened almost unnoticeably next to him.

"I think Kanda managed to catch me with his elbow when we were sparring – he can be pretty rough, you know?" Allen said, his pitch and tone off ever so slightly; had Lavi not been looking for it he never would have noticed the difference. The kid was a gifted actor, he'd give him that much.

"Mhm," Lavi replied, his eye twinkling with a knowing glint. Allen swallowed nervously and took another bite of food. "Maybe you should go to the Nurse, have her take a look at it." Allen choked, and Kanda thumped his back a couple of times. Was that a concerned expression, Lavi wondered. A downward turn of the mouth, perhaps, a crease between his eyebrows?

"No! It's nothing to worry about, I'm sure," he said, and chuckled, rubbing the back of his neck with a gloved hand. Lavi thought he saw him glance at Kanda, but the look they shared was so brief that Lavi didn't have time to decipher it.

He was silent for the rest of the meal, watching with the smallest of smirks as the two bickered like an old married couple, not missing the way their hands always remained beneath the table – how cute! Yuu-chan was holding hands with Allen.

"Shut up, moyashi!"

"Make me, baKanda!"

Lavi just smiled and took another sip of his lemonade.

Ah. Bittersweet indeed.