Kakashi shifts against the sharp edge of the desk and sighs. Naruto's getting better at this.
The slip-slide of a pink and agile tongue works hard at proving it, almost managing to coax a moan out of Kakashi but only getting a soft sigh, instead. Sighs, Kakashi thinks, are safe. They are an almost negligible sound; vague enough that they could mean everything or nothing at all. Kakashi would prefer, though, if Naruto were to continue thinking the latter so he works hard at making sure Naruto does.
Another swipe of a broad tongue gets a twitch that's really a well-restrained full body shudder in disguise. Naruto's getting a lot better at this. So much so that it's becoming all the more difficult to keep his eye on his book – his smokescreen, his diversion, his lie – and not on Naruto and his lips (wet, bruised, red and oh-so-decadently shiny) stretched wide, so very wide around Kakashi's cock.
The Academy classroom is the ideal setting for this. School is out for the summer and though Naruto hasn't been Kakashi's student for years, Kakashi can't help the perverted fantasies that run through his mind at the thought of doing this here. He never fantasized about any of his students back then – they were too young and he was their mentor – but now... well, things have changed enough that none of that matters. Naruto's all grown up and he wants this. Doesn't hurt that Kakashi doesn't mind giving it to him either.
Naruto looks completely at home down there on his knees; one hand around the base of Kakashi's cock, the other tightly clenching Kakashi's thigh as he bobs his head up and down. Kakashi knows where Naruto's hands are placed because he feels the pressure of them; he could see the white tips of bloodless fingers straining to grip his thigh if he looked. He doesn't. His eye skims words it reads but doesn't register instead.
A mass of blond spikes pointing haphazardly in every direction, Naruto's hair is in its usual state of disarray. It sways back and forth, in tandem with his every move. Kakashi can see the too-long strands over the top of his book and he tightens his fist in his pocket – not in of strands of blond that are both familiar to him and not. He swallows, licking dry lips and tasting damp, breath warmed cotton, instead.
To Kakashi, this whole scene feels like something that should have been in one of Jiraiya's novels. The eager student, doing his best to please his apathetic teacher; enthusiastically sucking cock because it may bring him the approval he craves slightly more than he craves the salty flavor coating his tongue. The very thought alongside the sight before him is enough to heat Kakashi's blood all the more.
Kakashi makes the mistake of taking his eye away from a page he has no interest in only to have it collide with wide, blue wonder. His breath catches in his throat and for the second time in as many minutes he has to hold back a groan. He wants to slide the tips of his fingers across scarred cheeks, feel himself through them as his shaft slides in and out from between soft, plump lips but he doesn't, forcibly curbing the impulse yet again.
Naruto's brow furrows in what must be consternation at the lack of response and Kakashi chuckles. It gets cut short, however, when a swallow constricts around the length of Kakashi's cock, throat sinfully tight. A pair of reddened, abused lips pull off with an audible pop and a wicked smile before diving back in.
Kakashi's eye narrows. Naruto seems so hungry for it but Kakashi recognizes the gleam in his eyes and Kakashi already knows he won't crack. Greater men and some women have tried and failed, although Kakashi won't begrudge him the opportunity to try. On the contrary, he takes it for the challenge that it is. Different from those he's used to with Gai, Kakashi intends to actively win this one.
He plans to make the book the center of his attention once more but Naruto is driven now. The hand on Kakashi's thigh slides into his pants and through the small opening, moving sinuously down and around to cup Kakashi's balls. Kakashi's eye threatens to roll itself back into his head but he forces its compliance in exchange for only the fluttering of an eyelid and a quick spike in blood pressure.
This weakness, however, does not go unnoticed. Naruto smirks around the cock in his mouth as though he's already won and Kakashi is lost because the blonde's arrogance only makes him hotter.
The movement of Naruto's mouth increases; he's no longer trying to suck Kakashi into a slow and agonizingly pleasant death. Instead, it all becomes a blur of pressure and heat and moisture. Lips and tongue play a swift tune, spreading sensation rapid-fire throughout Kakashi's body.
Naruto swallows, humming around Kakashi's cock in sheer enjoyment at making the older man squirm for once. The fingers that were cradling his balls are now ghosting around Kakashi's hole. It's all too much and not nearly enough, coalescing instantaneously into an overwhelming ball of want and need.
The long-forgotten book falls to the wayside and Kakashi's hands become entangled in Naruto's hair as he arches his back and comes hard, hips jerking, cock pulsing, down Naruto's throat. Kakashi's breath stutters traitorously in his chest as Naruto pulls off and milks the last of Kakashi's come out of his too-sensitive cock and into Naruto's open and waiting mouth.
"How did I do?" Naruto asks later; when Kakashi's had a moment to gather his composure. Naruto licks his lips and draws the back of his hand over them to wipe away the remnants of Kakashi's lesson. Naruto is still flushed and sweaty. The bulge of his cock visible where it strains against the tight confines of his pants. Kakashi's throat dries at the sight of the stretched material. Never before has anything orange looked so deliciously good.
Picking up his book and slipping it back into his pocket, Kakashi pretends to mull it over as he tucks himself back in and zips up his pants.
"There's room for improvement," he lies but when Naruto's face screws up like he's ready to argue the point Kakashi adds, "but I think you're getting the hang of it." And Kakashi can't help but wonder what other lessons he might like to learn.
"Yeah?" Naruto is pleased but a little uncertain. Where there once was teasing and arrogance, there's now hesitation and doubt.
"Yeah." Kakashi's eye arcs as he smiles his hidden smile, putting Naruto's fears at ease. Pulling Naruto towards him by the waist, his slim fingers are already moving to pull down a zipper. "Tell me, Naruto. What do you know about rimming?"
Pupils dilated, and with a slightly dazed expression, Naruto looks confused. He reminds Kakashi of his nin-dogs when they were puppies – dim and innocent and yet still somehow endearing – and Kakashi smirks at the sharp intake of breath he gets when his hand disappears inside.
It's time to start a new lesson.