The thing that Kakashi likes most about expanding the horizons of Naruto’s sexual education is that for all that Kakashi is actually attempting to teach the blond a lesson, Naruto has yet to even realize he’s being taught.
Even before this particular lesson began, Kakashi has spent hours with Naruto, painstakingly learning everything he can about his former student’s body. He knows what Naruto likes and dislikes; what will make him moan and beg or cry out in pleasure and what will make him stiffen his shoulders and shy away. He knows that if he laps at the hollow of Naruto’s throat, the boy will shake and shudder and curse at him all while holding his head in place so Kakashi can’t pull away. He knows that grabbing a firm globe of fleshy ass cheek in each palm will result in a deep, resonating moan that makes Kakashi break into a sweat just to hear it.
And he knows that as much as Naruto might try to say otherwise, he loves it when Kakashi spreads his ass and spears his tongue deep into the heart of him.
This is a lesson that Kakashi has most wanted to teach and teach it, he does, albeit slowly.
It’s light touches with the pads of his fingers on Naruto’s perineum while he nibbles down the side of his cock, at first. Getting him used to Kakashi’s long digits stroking and caressing places he wasn’t even aware could be stroked and caressed before.
It’s a spit-damp finger smoothing around his hole as Naruto lets loose ropes of hot, sticky come into Kakashi’s mouth.
It’s eventually diving right in the next time he’s mouthing Naruto’s balls. A slip-slide down to his ass that has Naruto jerking one stunned moment before coming all over his chest with a surprised grunt the next.
On one occasion, Kakashi spends what feels like hours with it. Hours after a week-long mission in the field catering to nobles and aristocrats who paid an obscene amount of money for two of Konoha’s most infamous for a simple body guarding mission.
It’s their first time alone after seven grueling days fending off nothing so dangerous as various groups of political toadies and other hangers-on, so Kakashi lays Naruto out on his stomach like a meal at one of the stuffy banquets they were forced to attend and licks into his ass, tongue unfurling the tightly wound muscle until it’s like so much putty in his hands. Naruto’s left gasping into the bed sheets, throat shredded and ripping pillow cases to shreds with his teeth as Kakashi’s plunges right in, tongue seemingly rubbing over each and every nerve ending until he has Naruto shuddering and shaking like a newborn calf.
He makes Naruto come like that—face pressed into the pillow as he nibbles and sucks, stroking his tongue deep until Naruto’s poor, neglected dick spurts out pulses of hot, wet come all over the sheets.
With the strength of Naruto’s reaction under his flak jacket, Kakashi considers the lesson nearly complete.
The only thing left to learn? How to return the favor.
With Naruto as his pupil, this is an expectedly difficult lesson to teach. But Kakashi is an expert at subterfuge so the lesson will be taught regardless of the difficulties this particular student brings to the table.
Kakashi’s eyes roll back into his head, orgasm rolling through him like a steamroller, dick spitting globs of semen all over his chest and abdomen. He pants through the last few strokes of a broad hand squeezing out every last drop and closes his eyes against Naruto’s shiny, blood-reddened lips and the filthy grin that lies there.
When Naruto snickers a few minutes later, he blinks one eye open and through the corner of it watches the grin nearly double in size. He raises an eyebrow.
Naruto props his head on a hand and snickers again. “I just rocked your world.”
Kakashi snorts and closes his eye once more.
A second passes and Kakashi swears he can practically hear the frown forming on Naruto’s still somehow cherubic looking face. He opens an eye again when sticky fingers prod his side.
“I totally just rocked your world,” Naruto repeats but he looks a little angry about it. Like he’s ten seconds away from yelling at Kakashi if Kakashi doesn’t agree with him.
“If you say so.”
“What the—what the hell is that supposed to mean?” The bed shakes as Naruto sits up. This time it’s closer to a yell but not quite up to the full capacity that he knows is a full on Naruto Yell in all it’s glory.
“It means whatever you want it to mean, Naruto,” Kakashi sighs, eyes closed again as if he can’t be bothered.
“What. You. Are you saying—are you trying to tell me I didn’t just blow your brains out through your dick? Because if that’s—if that’s what you’re saying, I think I’m gonna have to disagree.” Kakashi feels the displaced air as Naruto waves his hand around at Kakashi’s naked and presumably sated body as if to say: Please see Exhibit A as evidence.
Kakashi lets himself smirk a little. “If you say so.”
“You...” Naruto seems at a loss for words. His brow is probably furrowing in that cute way it does when he’s frustrated. “Shut up.”
Kakashi eyes blink open.
“Yeah, shut up. I know you’re just—you’re messing with me. Trying to pretend like you didn’t just get your world rocked by the sex god Uzumaki Naruto.” Naruto attempts a smirk and Kakashi snorts again.
Naruto’s face gets this pinched look on it – lips pursed, eyes narrowed... you know, pinched.
“The Great Sex God Uzumaki Naruto hasn’t even tried rimming yet.” Kakashi looks away as he speaks, like he doesn’t care but is just pointing it out to needle Naruto anyway.
Naruto makes a face. “What, you want me to—“
“I’m saying you haven’t tried it. Don’t go ahead calling yourself a ‘sex god’ if a little tongue action scares you.”
“I’m not scared!” Naruto cries, indignant.
Kakashi just raises an eyebrow as if to say, Yeah, you totally are, you big sissy.
“I am not!” Naruto kneels up on the bed, hands on his naked hips. Kakashi’s eyes dip, following the line of hard abdominals and a trail of dirty blond hair for a second—
He clears his throat, flicks his eyes back up. “If you say so.”
Naruto’s eyes widen. His lips thin and face flushes that dull, ruddy red it gets when he’s really angry. Or frustrated. Or when Kakashi teases him. Or plays with his dick. Or does that thing with his tongue that makes Naruto whimper so delightfully. Or—
“If I’m gonna do this, you have to. Roll. Over.”
“What, now?” Kakashi just barely manages to keep his jaw from dropping. Despite all the shit he just gave Naruto about not really ‘rocking his world’, Kakashi just came really hard. He’s not sure he could—
“Why not now? Can’t get it up again so soon, old man?” Naruto taunts.
Kakashi narrows his eyes. “Fine.”
They glare at each other some more.
Kakashi glares one last glare before rolling onto his stomach.
And then he smirks.
The first time Naruto attempts rimming is... ehh. Kakashi’s almost glad he came so hard in the moments before that because the knowledge that it was Naruto’s first time performing the act had him stiffening up faster than he’d have thought possible in a shinobi his age. Coming into it fresh would definitely have given him a hair trigger the likes of which would have given the blond an even bigger ego than he had already. As it was, Naruto barely even touched the skin between the dip of his ass with his tongue before he found something to argue about so he could stomp out of Kakashi’s apartment angrily.
Kakashi was left a little frustrated but thankfully not painfully so.
The next time, however, was better. Kakashi didn’t bring it up, wasn’t even expecting to see Naruto before the week was out but the blond showed up two days later with a determined look in his eyes. Kakashi was ass up, naked on the bed, before he could blink with Naruto staring at his ass like rimming was the next great jutsu he had to master.
It turned Kakashi on more than he let on, if he were to be completely honest. Having all of Naruto’s attention focused on him always made him want to pause and soak it in. It was the same whether Naruto was on his knees with his pretty pink lips wrapped around Kakashi’s cock or leaning over him with his hand wrapped around his dick as he jacked Kakashi hard and fast. Once Naruto decided to do something, he didn’t half-ass it. It was part of the reason Kakashi thought teaching Naruto was so fun in the first place.
So the next time was better but it wasn’t fantastic. They tried it a few more times in between the normal, every day sex they usually had – mind-numbingly good blow jobs, toe curling hand jobs, and some frottage that was better for loosening his muscles than any chakra massage he’d ever had – but it never seemed to ‘rock his world’ like Naruto seemed convinced it did.
Naruto’s technique gradually improves after that, until one day it just... seems to plateau. He hasn’t yet become an ass eating guru or anything like that but he’s passable. He still hasn’t managed to turn Kakashi’s brain to mush with a flick of his tongue but Kakashi figures that Naruto’s put forth enough effort and is willing to consider the lesson complete if only so he can mentally move on and focus on the next lesson.
If he’s a little disappointed, he makes a point of never showing it.
Long, callused fingers run down Kakashi’s naked back and into his open slacks. They’ve curved in just the right way around his ass when the question is asked, or, well, alluded to.
“You want me to...” Naruto trails off, waggling his eyebrows suggestively as he gives the flesh under his palms a squeeze.
Kakashi chokes back a smirk at Naruto’s ridiculous face. “Mm... no, that’s okay.” Which, he figures will move this session on to more pleasurable activities but it turns out, is exactly the wrong thing to say.
When Naruto goes still as a board, Kakashi does too, mind already a whirr of half-formed plans and ideas worked up on the spot in a hopeful attempt to fix whatever the problem is so he still gets sex. Shinobi have needs, Kakashi – who’d just returned from a two week long mission to Wind – moreso than others.
“No? How could you say ‘no’?” Naruto’s eyes are wide and his stance is giving off warning signs that Kakashi doesn’t know what to do with.
“I’m... sorry?” Kakashi hedges, not really understanding the problem but knowing that apologies are the first step to working your way back into someone’s good graces or, in this case, their pants.
“You’ve never said no when I’ve offered to, to, to, you know!”
“To put your thing in my mouth,” Naruto lowers his voice, whispering harshly.
“Or when I ask if you want me to,” Naruto makes a lewd gesture with a mostly closed fist, simulating a hand job, Kakashi’d guess.
“Oh, you see...” he starts and then promptly trails off because what can he say, he doesn’t really have an answer for that. What red-blooded shinobi would turn down any of those things? And from their favorite pupil, at that.
Naruto gives him a dirty look and next thing he knows, he’s standing five feet away, arms crossed and not anywhere near Kakashi’s ass. Kakashi stifles the groan that wants to burble up out of his chest in frustration. His dick is a hard, solid line in his briefs and Naruto wants to ‘talk’.
“I’ve never said no, when you've asked!” Even worse, he’s skipped ‘talk’ altogether and moved right on to the ‘yell as loud as he can while waving his arms around like a maniac’ portion of the evening.
Kakashi slides his hand into his pockets, willfully ignoring his painful erection and tilts his head, a small smile on his face. He’s never said no because at rimming, Kakashi is King.
Naruto face turns that shade of red that Kakashi loves again and averts his eyes. Oh yeah, Naruto knows it too.
“Stop that.” Naruto says but to Kakashi’s ears he sounds like a soon to be debauched schoolgirl saying, ‘no, no, no’ when she really means, ‘yes, more, fuck me like you goddamn mean it you rotten bastard.’ With his eyes turned away he doesn’t see Kakashi close the distance between them faster than most civilians can blink.
“Why, Naruto.” Kakashi coyly slides his arms around the blond’s waist. He smiles when Naruto doesn’t startle at the sudden change in proximity. “Are you trying to get me to lick you?” His voice is a deep, low rumble, lips brushing the shell of Naruto’s ear. “Down here?” Kakashi rubs at the crease of Naruto’s ass through his pants and boxers, trying to get through the layers to the tight furl of muscle beneath it. Kakashi nips at his ear with his teeth and Naruto shudders, hands suddenly tight on the other man’s bare shoulders.
But when Naruto pushes Kakashi away a second later, Kakashi doesn’t stop the groan of frustration this time. Naruto is flushed and clearly craving what he knows Kakashi can give him, what he has to know Kakashi would like so dearly like to give him, and the sight of it makes something needy twist in the pit of his stomach. “No, I wanna—I wanna know. What—Why don’t you want me to... do... that.”
Kakashi sighs, pulling back and releasing Naruto completely. “There’s no big reason, Naruto, it just doesn’t feel as good as—“
“What do you mean it doesn’t feel good?”
Kakashi quickly attempts to placate. “No, no. It feels fine, just—“
“FINE? It only feels FINE?”
Kakashi stares. Naruto is seriously upset because Kakashi didn’t want him to rim him? Naruto hates doing it, why the hell does he even care...
“No. Get your ass on the bed, pants off. We’re gonna do this.”
Naruto is a stubborn bastard. More stubborn than Kakashi even which is why he decides not to argue and just takes off his pants. His dick is still throbbing in his boxer-briefs and he looks down at it. Can’t help but think that he won’t be getting any relief soon. He sighs again.
“I’ll show you fine,” Naruto mumbles under his breath as he angrily strips his own shirt over his head.
“Naruto, you don’t—“
“Is there a reason you’re not naked and on the damn bed already?” Naruto snaps.
Kakashi blinks. His dick twitches in his briefs and he looks down at it again, this time with a frown. Traitor.
When he next looks up, Naruto has stripped all the way down to his boxers. He doesn’t get to appreciate the sight of that well-toned body, only gets a glimpse of the blonde’s determined face before Naruto’s moving towards him, pushing him face down on the rumpled bedcovers and yanking his underwear down around his knees.
There’s barely enough time to grunt when his face hits the sheets and then warm puffs of air are fanning out against sensitive skin. When he looks back over his shoulder, Naruto is on his stomach, staring intently at his ass.
Kakashi fidgets uncharacteristically under the scrutiny. This isn’t anything like how it goes in Icha Icha...
“Stay still,” Naruto orders, with a slap that makes him jerk in place.
Naruto starts with a few soft, tentative licks that manage to raise Kakashi’s blood pressure a bit but not much else. Not much different from how he usually does it. Naruto’s eats ass like he’s daintily licking at a lollipop or an ice cream cone when Kakashi wishes he would be a little rougher. He heaves a sigh. This does not go unnoticed by Naruto.
The next swipe of his tongue comes a little firmer; he shifts his hips in response. Naruto must take notice because the following swipes of tongue come back with the same firm pressure that makes Kakashi clench against it.
“Huh,” Naruto says. Then he does it again. Kakashi’s ass clenches against the sensation again almost involuntarily.
Naruto chuckles. “You winking at me, Kakashi?” The purr of sound rolls right up against the sensitive nerve endings in his skin shocking a gasp out of him. Kakashi groans and hides his warming face in a pillow. He doesn’t need to look to see it the grin that has to be on Naruto’s face. And, okay, Kakashi thinks, that’s definitely new. Naruto’s not much for teasing; he prefers to take direct action, taking or giving what he pleases. Anything requiring finesse is usually beyond his scope of ability but that. That seductive purr and the clear enjoyment in his voice isn’t something Kakashi has witnessed before and he shudders hard.
“What, you like that? You like me saying dirty things like that? Guess you really are a pervert.”
“Naruto.” Kakashi warns, against what he doesn’t know.
“Mmhmmm?” Naruto hums against his skin.
And now Kakashi can’t speak at all. His voice is lost somewhere high in his throat and instead of words, out comes the most unintelligible sounding whine Kakashi has ever produced in his life. It is, quite frankly, embarrassing of a shinobi of his age and stature and his body flushes red even as the sound escapes him but he doesn’t have time to think about it long because Naruto does this thing. Something new that he must have made up on the spot; it’s half twist, half stab, half slurp, all tongue and Kakashi’s eyes cross as he humps down into the bed and is gone. Far, far and away.
Kakashi doesn’t hear the chuckle when he comes.
Some indeterminable amount of time later Kakashi groans himself back into awareness. He thinks he might’ve blacked out a little there but he’s not entirely sure. His spine feels like limp ramen and he’s covered in a thin sheen of sweat. At the small of his back is a damp puddle of come. Damn.
“So?” Naruto says and there’s something entirely relaxed and gleeful in his tone.
“You can go ahead and say it, you know.”
There’s a long pause and the hand on his ass squeezes.
Kakashi stays stubbornly silent.
“You’ll say it if you ever want me to do it again,” Naruto cajoles. He doesn’t bother shouting or making threats this time because he knows, dammit.
Kakashi glares weakly at Naruto. His aloof and usually unaffected mask have all deserted him in the aftermath of one mind-blowing orgasm.
Naruto’s hand glides through the sweat on his back, fingers trailing down through the streaks of rapidly cooling come, over the curve of his ass, thumb tickling at the edge of his hole. His whole body twitches involuntarily, the traitor.
“You want me to do it again, don’t you, Kakashi?” Naruto’s voice is liquid sex and Kakashi can’t even find pride enough to think I did that. I taught him how to sound like that.
He sighs instead, defeated, and mumbles, “World rocked.”
Naruto snickers as he rolls onto his back but Kakashi? Kakashi. Doesn’t. Move. A. Muscle.
His world has been officially rocked. Lesson Complete.