They'd never been anything but honest with each other. Their relationship (friendship, rivalry, brotherhood?) may not have been perfect, but it was certainly honest. Plainly, sometimes brutally, honest.
"I promised I wouldn't die until I killed him...my brother...He's still out there."
The outrageous.
"I always...hated you...Naruto."
"I...I always hated you too...Sasuke."
"You're one of the ones I want to fight the most."
The heartfelt.
"My precious comrades, falling right before my eyes..."
The painful.
"You were on your own right from the beginning, what makes you think you know anything about it?! Huh?!"
"And whenever I'm with you...I think, maybe...That's what it feels like to have a brother."
"You are my closest friend."
Nothing was ever hidden between the two of them. They were transparent to each other.
"So can you tell what I'm thinking, Naruto? Do you know what's on my mind?"
So now, staring into his eyes-
"Your life was spared on a whim."
-he has to force himself to keep a straight face. Because it makes him want to laugh. He knows what Uchiha Sasuke sounds like when he's telling the truth. And right now, well...
The dark-haired boy's attempt at bluffing is almost cute. And he knows it.