In Plain Sight
Sasuke envied Naruto for a lot of things, but most of all for the way he could see people.
For instance, when Sasuke encountered Gaara of the Sand, he saw 'enemy'.
When Naruto fought Gaara, he saw 'loneliness, sorrow, isolation, depression, despair, wanting, needing, betrayal, reaching, begging, hurting, strength, hope, hope, hope'.
It's because of this quality that Sasuke thinks Naruto can love Sakura more perfectly than he ever could, so he doesn't stop his teammate's irritating if admirably relentless romantic pursuit. Sasuke also acknowledges that Naruto will make it easier to leave her behind.
In Sasuke's world, people were flat and colorless. He liked it that way, because complexity derived emotion, and emotion was something he could ill afford. Sasuke doesn't think he even knows how to truly care for another.
Still, he's not completely immune to the pitfalls of a human heart. Anyone could understand it was hard to see in black and white when her eyes were so green and her hair so pink.
There are flashes when he catches a glimpse of the Sakura Naruto worships with stunning clarity. (Sasuke's eyesight is both a curse and an honored birthright.) Instances where time stills and her hair is flying as the death blow nears- his stomach never dropped to his knees so fast as when he thought she'd be gone in the next instant.
Another moment, where she is strong, sweaty and beat up. He notices her musculature, how tense it is and how fierce her eyes are before the sand knocks her aside. But for the second she stood in front of him he never felt safer.
It's in the inches she closes with her arms when all he wants to do is break them. Then she's warm against his back, weeping and begging him to stop. He never wanted that for her, so he finds strength he never knew he had in himself to force the ugliness back down.
Never, never, never. With nothing to offer, and so much to lose, that's all his future with Team 7 could amount to- strings of broken promises and disappointments.
When he leaves, he wishes he never saw the world through Naruto's eyes, because it's spoiled him for the coldness ahead. When he leaves, he wishes he had never looked at Sakura when his gaze was warmer, because it's spoiled him for the loneliness he would've mistaken as tranquility before her.
He especially wishes he never noticed any of this when he sees her again years later, when all the moments, and inches, and sweetness have knitted together seamlessly into a woman he doesn't want to know but recognizes all too well.
He feels decidedly grotesque next to her, twisted and unnatural. She sees his falter in confidence and capitalizes on it. Hardly believing it, he falls to her attack. He never hits the ground, because she caught him, and now she's kneeling and holding him so tight his ribs creak. She's stronger, much stronger, and yet, Sasuke never remembered her body being so small compared to his.
She's crying all over his shirt.
He should be horrified that a ninja who couldn't even manage to stem the flow of tears beat him.
He should be thinking 'HOW'!
Instead, he's realizing he doesn't need a softer gaze or even his sharingan to see what it was Naruto always knew- now it is in plain sight.