Kakashi-sensei had just left his genin team for the day and was on his way to the ninja academy. He grinned under his mask as he leapt from rooftop to rooftop. He was early. That would be a surprise for his favourite chuunin teacher. Early. He'd have at least half an hour to sit while Iruka graded the day's quizzes. Half an hour to watch a delightful parade of expressions, exasperation, amusement, disappointment, pleasant surprise, pass over his lover's delightfully expressive face.

It was a feast for a dedicated Iruka watcher like him. Not only that, but it was the perfect opportunity to work on flooding him with lecherous intent.

The first time he'd tried this it had only been a few minutes before he'd made the man get up from his seat, walk over to him, and almost pin him flat against the desk he'd been lounging on with the force of an impromptu, tonsil-wrangling kiss. Ah sweet victory. Of course that was before Iruka had realised what was going on. Last week, once he was on to him, he'd held out for a full ten. It was better than teasing him. Or rather it was teasing on a whole other level.

He approached the classroom silently, as he always did, perching on the windowsill to peek inside. His heart fluttered at the wonderful sight. Iruka-sensei, on the floor, on all fours, with his perfectly tight little arse sticking up, like an invitation to naughtiness. As he eased the window sash open Kakashi scowled and clicked his tongue lightly, apparently Iruka was too focussed on something else to notice. He'd have to scold him for that later, maybe even spank him gently on that sweet little arse. But later. Right now there were other things on his mind. He slipped into the classroom and crouched behind his target, cupping one hand around each perfect butt cheek.

He felt the body beneath him stiffen. "What the hell do you think you're doing you jerk?"

Kakashi stretched an arm to the floor on either side and leaned forward, breathing into a caramel ear. "Isn't it obvious? I'm seducing you Iruka-sensei."

The chuunin pushed back, forcing him to fall backwards into a sitting position. "Well get off you pervert. Can't you see I'm busy?'

Kakashi pouted at the loss of contact. Then noticed an open box and a variety of odd little wood and metal pieces scattered on the floor. He had seen them when he first entered the room, but had assumed they were the debris left after some kind of ninjutsu demonstration. They hadn't registered in his conscious mind.

"What is it? Some kind of puzzle?"

His hand reached out to pick one up. The teacher turned to him with the glare of death. "Don't touch those! You'll lose them, and… and mix them all up."

Ouch. He dropped the steel rod and pulled down his mask, revealing his very best guilty, apologetic, scolded puppy, half smile. It was a heartbreaker and he knew it. "I'm sorry, I only wanted to help."

Iruka had no defense against such ruthless tactics. His expression softened and he leaned over and kissed Kakashi's, now bare, cheek. "I'm sorry too. I didn't mean to snap, it's just that I think I've finally got them into some kind of order."

The teacher sat back on his heels, warming to his subject. "I just got it today, a new weapon. It's really cool, a kind of crossbow that shoots bolts you can attach exploding tags too. It's as silent as a hand thrown shuriken or kunai but with five times the range and at least as accurate. And it folds up to fit into a pouch or tuck into a belt." His enthusiasm wavered as he added. "I just didn't expect it to come in quite so many pieces."

Just then the classroom door flew open and Konoha's loudest ninja blasted in. "IRUKA-SENSEI!" Naruto came to an abrupt halt. "Say just what areyou two doing down there on the floor?"

Kakashi's mask was already back in place. Iruka scrambled to his feet, pink blush spreading across his cheekbones.

"Er nothing… er, that is we were just trying to put this together."

The boy surveyed the scattered pieces.

"What is it? Some kind of puzzle?"

Iruka lowered himself back down and picked up a metal ring. "No it's a new weapon, but we're not quite sure how it all fits together. There are a lot of little bits so I suppose it is kind of like a puzzle in a way."

Naruto knelt beside him. "Sure are, p'raps I can help. I used to do a lot of puzzles, you know, being on my own so much as a kid."

Iruka looked away as a lump formed in his throat. Even Kakashi was touched by the boy's stoic acceptance of his lonely past. He looked up to see a dark shadow in the still-open doorway.

It spoke.

"Have you seen the dobe, he was supposed to train with me this afternoon."

Sasuke walked slowly into the room and calmly regarded the three figures kneeling on the floor. "So you're letting Naruto join in but not me?"

Naruto looked up at him, grinning widely. "Hey Sasuke-bastard. Don't just stand there, help us out with this thing."

Sasuke stared impassively at the mess on the floor.

"What is it? Some kind of puzzle?"

"Er, no, er it's… a new kind of er, crossbow actually." Iruka was blushing again. But his flushed face and stuttering came not so much from having to explain, as from the hand he could feel stroking his inner thigh, dangerously close to the boys' line of sight.

Sasuke's knowing eyes spoke volumes but his lips remained tightly closed.

Naruto jumped up, sliding a peg in and out of a corresponding hole. "Hey! These two bits go together. See one fits into the other perfectly."

Sasuke kept his gaze on the two senseis as Iruka's face turned from pink to crimson. "No dobe. The longest thickest stick has to go in the middle. We should join in the others from there."

Iruka's face turned scarlet.

The eardrum shattering squeal was almost a relief. "Iruka-senseiii, have you seen the guys? They ran off without me. Why is it Sasuke always want to spar with Naruto and never with me anyway?"

Sakura stopped a few feet inside the classroom. "Oh, you're all on the floor… together. And what's that? Some kind of puzzle?"

Naruto flashed his brilliant grin. "It's a cool new weapon Iruka-sensei just got. We're helping him put it together."

The girl took in the scene. "Oh." She took a few steps towards them. "So where's the box?"

Iruka pointed behind him. "Over there, but there's nothing in it, I already took out all the parts."

She gave him a dubious look, familiar to all females who spend their time almost exclusively around males, walked over and picked it up. Then reached inside and took out a small printed booklet. "Just as I thought, assembly instructions."

"What?" The four males on the floor said in unison.

"Ass-em-bly in-str-uct-shons. You know, to tell you how to put it together." She flipped through a few pages. "See, you're doing it all wrong. You have to put the firing mechanism together first, then assemble the side arms. The big shaft slides in last."

Her eye caught Kakashi's and she blushed as red as her former academy teacher. Then muttered to cover her embarrassment.

"Really, I'm not surprised at you two geniuses not having a clue, but I'd have thought you'd have more sense than to ignore the instructions Iruka-sensei."

"Hey what about me, what about me?" Naruto demanded. "Do you think I don't have a clue, or should I have more sense too?"

Sakura ignored him.

She set the booklet on the floor in front of her, scouted around for the right parts, swabbed them with glue, and screwed them into place. In a remarkably short time she was holding a strange, but recognisable, crossbow.

With a last quick inspection of her work, she handed the bow to Iruka. "Come on guys, let's go and train before it gets too dark. I'm sure Kakashi-sensei and Iruka-sensei can finish off without us now. Just make sure you let the glue dry and tighten all the fastenings."

Sasuke stood up and looked at the two men still kneeling on the floor, letting his dark eyes sweep from Kakashi-sensei to Iruka-sensei and back. They stayed there, holding him with their unwavering gaze. "Yes, I'm sure they can finish off without us. But remember to screw it really tight. You don't want a powerful weapon like that going off in your hands and making a big mess."

Naruto rushed off to join the other two as they disappeared out of the door. "BYE IRUKA-SENSEI!"

Iruka stood up putting his new toy on his desk. "Women. They're the real puzzle. How can she be so completely clueless about Sasuke but then shame us all with her common sense?"

Kakashi rose effortlessly to his feet as he eased his hand over the Iruka's pert rear, squeezing gently at the juiciest part. "Yeah, Sakura often gets overshadowed by those other two, but she really is quite something."

His other hand flattened itself over the teacher's crotch kneading lightly and provoking a gulp and a breathless groan. "So now that you're not busy anymore, just where were we? Wasn't I about to seduce you?"

"Kakashi?" The teacher's voice was muffled by the taller man's throat because he had wrapped his arms around his neck, pulling him closer and leaning into him for support. He was feeling remarkable boneless suddenly. "You don't think the kids suspect anything do you? You know, about us?"

So he'd picked up on that crack about a weapon going off in someone's hand. He squeezed the firm weapon beneath his, getting another low groan in response. Obviously Sasuke and Sakura had worked it out a long time ago. And Naruto? Either he really didn't have a clue or he had more sense than to let on. Knowing the boy's level of discretion, most likely the former. But right now wasn't the time to let Iruka get distracted and self-conscious.

"Don't worry about them. Whenever they're ready to understand they'll put the pieces together. Just like some kind of puzzle."