“You’ve Found My Library, Welcome…”

The feud between you has been simmering for two years at this point – and it runs deeper than the clipped cadence of his voice when he speaks to you, or the ridiculous leopard print tie he favours so much, or even the suffocating pragmatism he wields like a second blade.

No, what truly grates is your differences in philosophy, the way they surface in every battle, every mission. To him, you’re reckless. To you, he’s inflexible. Stuck up. Condescending. If someone asked him directly, he might have a few choice words to describe you in return.

Still, the higher-ups thought they were clever, pairing your technique with his. Perfect synergy, as they called it. Too valuable to waste. The younger sorcerer brimming with potential, paired up with the seasoned veteran to temper her recklessness.

Stuck together, as you preferred to call it.

And the thing was – you’d actually managed to make it work. Somehow, despite your fundamental differences, baring a few squabbles and disagreements here and there, you fought well side by side. You covered each other’s weaknesses, filled in each other’s gaps.

At least, that’s how it used to be.

Until the mission in July happened, that is.

Ever since then, Nanami has never treated you the same.

You hear it in his tone, now sharper than usual, the way he won’t meet your eyes and yet his gaze lingers on your back like he doesn’t quite trust you to execute a simple assignment without tripping on your shoelaces, and in the way you sometimes catch him staring at the jagged scar running down your left arm – the injury you’d sustained from the mission – his lips pursed and brow creased.

On the surface, things carried on as per usual. You were still being paired together to tackle harder missions better left to more experienced sorcerers. Nothing had really changed about your dynamic, either. You still go out of your way to annoy him, and he still remains unimpressed by your attempts to push his buttons. Most importantly, the implicit trust between two partners on the battlefield was still there, unbroken.

But underneath, you knew that the air between you had permanently shifted, charged with a tension you couldn’t quite name. Sharp and lingering, it polluted every interaction, every word too heavy, every sentence too loaded.

Sometimes, you wondered if it was hatred, that maybe after your fuck up in July he’d decided you weren’t worth his respect anymore. That the semblance of friendship you’d been slowly progressing towards no longer meant anything. Or maybe, that the scar on your arm was such a jarring reminder of your failure that he could no longer bring himself to look at you without remembering how badly you’d messed up.

And after tonight, when you’d come so close to messing up again, it feels even worse.

Nanami hasn’t said a word for the better part of an hour, weary eyes fixed on the dark ribbon of highway ahead. His jaw is set in that way that means he’s stewing – about you, about the mission, about the split-second decision you made that forced him to step in and save your ass.

Oh, and about the fact that you were supposed to be back in Tokyo by the afternoon, and it’s 9pm.

The next day.

Working overtime. He hates that shit. Possibly even a little more than he hates you.

Nanami’s sleep deprived – you both are – but the difference is that whilst you’ve been able to take little naps in the passenger seat, he looks like his restraint is being held together by the last shreds of sheer willpower and caffeine. He’s on third, maybe fourth cup of cheap convenience store coffee, and his hands are clutching the steering wheel so tight his knuckles have gone white.

For the record, you’d sincerely offered to take over the wheel, but he’d insisted on driving, claiming he didn’t trust you on the road, or with his car.

You’re stealing glances at him – his typically crisp dress shirt rumpled, tie loosened (thank god he took that monstrosity off), fatigue carved deep in the lines of the stone statue that is his face. He’d let you have the bed last night, when you were stuck in a shitty motel with only one room available, whilst he slept on the floor with a spare pillow and a towel draped over him to act as a makeshift blanket.

So really, you should probably feel a little guilty.

And you do, really, you do. You just can’t sit still in the quiet for any longer.

Your lips twitch, and you reach for the console to turn the volume up a notch.

“Don’t,” Nanami says, without looking.

Your fingers rest on the display, smudging a little fingerprint across the surface of his otherwise pristine touchscreen – because of course the man keeps his car immaculately tidy and maintained like he just drove it out of the Mercedes dealership the day before.

You hover over the volume button, then, whilst meeting his gaze, you slowly drag your fingertip in a tiny crescent. The bass lifts just a breath – some obnoxious song on the radio you’re only going to pretend to like when he tells you to turn it off – and you hear him audibly exhale.

Nanami’s jaw flexes. “Off.”

Bingo.

You feign a pout. “You haven’t even heard the song. It’s my favourite, you know.”

“Doesn’t matter,” he replies, voice flat. “My car is not a club.”

“Disagree,” you say, tapping the dash, where the LED panels extending across the length of it alternates in the colours of the rainbow, pulsing slowly . “You have the lights. You’re just lacking the vibes.”

He ignores the last end of your statement. “I told you not to mess with my settings.”

“Why buy a fancy car if you don’t play with it a little, Grandpa?” You grin at him sideways, knowing full well the nickname makes his eye twitch every time.

Nanami isn’t one for overtly emotional displays, but it’s the little chips in his composure – so tiny you’d have to squint to see it – that makes pushing his buttons so entertaining. He’s normally a lot better at denying you the satisfaction of seeing it happen, but now, when sleep-deprived and running low on patience, those cracks show easier.

“I am not your grandfather,” he mutters.

“Could’ve fooled me,” you hum. “You sure drive like one.”

“I drive safely.” His gaze flicks to you, entirely unimpressed. “If I’m being honest, I preferred when you were asleep. It would spare me your commentary.”

Oh, good. He’s talking again. Talking is good. Anything is better than the silence he’s been submerged in ever since the mission ended.

“Don’t be so mean, Kento,” you sing-song, drawing out the “O” sound to his name. “I happen to like talking to you.”

That’s a half-truth. You like getting on Nanami’s nerves, mainly because you seem to be able to draw a reaction out of him unlike another other. Not even Gojo comes close, and that’s saying something. He’s just a lot more… reactive when it comes to you, and even though you can't figure out why, you’ve always been more than happy to exploit that fact.

And the other half of it? Because any reaction is better than the suffocating quiet that engulfs the car. That, and the sidelong glances of contempt he’s been casting you. You’ve been itching for an argument, and you understand Nanami well enough to know that he’s biting his tongue, holding back on the things he truly wants to say. So why not speed the process up a little?

a/n: this fic is largely motivated by my need to write a realistic enough scenario where i could imagine nanami hate fucking the reader… i think it’s fun to explore different sides of his character besides a typical perfect husband! although he still very much is a gentleman here heh