Chapter Text
Sometimes, Sasuke wonders whether they deliberately designed the ANBU uniform to be sexy.
Because it is, and there's no two ways about it. A tight black top, sleeveless to show off the wearer's invariably muscled shoulders and biceps, further highlighted by those long black gloves. Some of the masks are kinda creepy, but they've got kinky potential...yeah, Sasuke's definitely into it.
Now, you're not technically meant to know who's in ANBU: it's on a need-to-know basis only. But after you work with someone for a while and get to know their movements and voice, and then that same voice and those same mannerisms turn up on some supposedly-anonymous masked ANBU...and that's not even accounting for the myriad ways in which one might catch sight of an ANBU tattoo (a practice which Sasuke has never understood the point of, by the way). Itachi's usual high-collared Uchiha shirts have sleeves which cover his tattoo, so no-one thinks anything of it, but it's not like he can hide it from Sasuke when they still share baths.
Itachi looks the best in his uniform, of course, because Itachi looks best in everything. And in nothing, as Sasuke has learnt from the aforementioned baths. He's never seen Itachi get dressed in his ANBU uniform, but he likes to imagine it, especially the smooth stretch of the gloves and the solid weight of the armguards.
And as for what Itachi does in that uniform — images of his brother calmly and efficiently slitting a faceless man's throat make him squirm and touch his fingertips to the inside of his thigh, drawing out the pleasure.
Sasuke thinks of his brother's large, long-fingered hands, and imagines them wrapping around someone's throat; the image is interspersed with the impossible dream of Itachi's hand around Sasuke's cock. Sasuke's in the middle of puberty and growing out of his clothes every few months, but Itachi still has twenty centimetres on him, and his hand would engulf Sasuke from root to tip. He wants it so badly his chest hurts.
The moment he's been waiting for arrives: the front door slides open, making only a whisper of noise, but one which Sasuke is well accustomed to. His brother's footsteps are soundless, but Sasuke can track his progress down the corridor, past Sasuke's room to his own. Sasuke imagines him, all dressed up in his ANBU gear, flak jacket stained with blood, and his pulse quickens. He imagines Itachi pausing in front of Sasuke's room and instead of continuing on to his own, entering Sasuke's.
He listens intently to the rustles and clinks of Itachi's disrobing, and tries to assign each sound to its item of clothing: the clinks of the shuriken holster, headband and armguards, the thump of the jacket and sheathed katana, the snap of the gloves, and finally the rustle of fabric. Sasuke imagines the striptease, the insignia of rank removed to reveal pale flesh until his vision of Itachi stands naked before him, lithe and pale, luminous in the moonlight, his hair unbound over his shoulders.
In the other room, the sheets rustle as Itachi gets into bed; in Sasuke's head, behind closed lids, he crawls into Sasuke's bed, the futon dipping under his weight. Sasuke can almost imagine his body heat.
He gives in at last, imagining Itachi lying beside him as he takes his cock in hand and squirms with pleasure. Itachi - the real Itachi - will know, of course: there's no way he's fallen asleep so quickly. The possibility of his older brother listening in and knowing what he's doing both scares and excites Sasuke, the fear only intensifying the thrill. In any case, there's no way that Itachi could ever know what he's thinking of while he's doing it (but Itachi has always known everything about Sasuke, been able to divine any fact, any secret, just with a glance, so what if - but that's too scary to think about).
Sasuke masturbates himself to climax listening to Itachi's breathing in the next room, steady and just a little too fast for slumber.