I hate you!
The words echo over and over in his mind, constantly repeating themselves like some sick, twisted mantra.
He doesn't know when things went so wrong. He doesn't understand how it happened so fast, how Tidus could go from loving him to hating him in what felt like mere seconds.
And he doesn't know why it should hurt so much.
When he first came to Zanarkand, he hadn't started out caring whether or not the boy liked him. He had made a promise to Jecht, to raise his son so that one day he could bring Tidus to Spira as Jecht wished. It was as simple as that. Emotions hadn't factored into the equation.
He hadn't counted on the boy himself. Small, stubborn, and defiant, Tidus poured as much energy as he could muster into hating his father. His anger seemed to know no limits, putting him into a fit of rage if someone even so much as mentioned Jecht to him.
It had fascinated Auron. He had picked up throughout Jecht's stories that Tidus hadn't liked his father much, but he hadn't realized just how much until he witnessed it first-hand. He wanted to know why, just what it was that made the boy hate the man. Jecht had been a bastard, but he had obviously cared for his son. He never shut up about wanting to get back to Zanarkand and see them.
He had decided the only way to find out the reason why was to get Tidus to like him. And when the boy's mother died and Auron was all he had left, it really didn't take long for Tidus to start looking to him for support, and even less still to turn into some kind of hero-worship.
Auron wasn't exactly sure when he'd started caring for Tidus in return. Perhaps it was the time he found him out on the dock in the rain, soaking wet and cursing Jecht with all his might as he pounded his fist over and over onto the ground. Perhaps it was the first time Tidus had a nightmare and came to him in the night, crying silently and tightly hugging a small stuffed chocobo, his eyes pleading with Auron for comfort. It didn't really matter when.
Somehow Tidus had gotten past Auron's defenses and made him care. And somewhere along the line, that caring had turned into something more than akin to paternal. Somehow, as Tidus had grown from a small boy to a young man, Auron's affections had grown from platonic to romantic.
He'd done his best to keep it to himself, not wanting to screw up the comfortable relationship they had. But when Tidus started to apparently have feelings of his own, and actually attempted to do something about it, it had been becoming increasingly difficult to resist.
He knows that something had had to give eventually. He knows that no matter what, the situation would have been brought up by one of them, at some point, putting it completely out in the open. But what he did not expect, what he does not understand, is the violent reaction Tidus had to it. He didn't deny the accusations nor the feelings, so why had he been so upset at Auron at last confronting him about it?
Shut up! I hate you! I don't want to talk about it!
Tidus had shouted those words at him, glaring all the while. Anything Auron attempted to say after that was cut off by Tidus repeating some variation of those words, until at last Auron had conceded defeat and left the boy alone.
He knows that he has irrevocably broken something between them, something important and fragile, even if he does not know just what that something is. He wonders if Tidus really hates him. He wonders why Tidus is so afraid of chancing a real relationship between them when he obviously wanted something more than what they had, if his past actions had been any real indication.
He wonders if Tidus will ever speak to him again, or if he will be cursed to have I hate you! be the last words he'll ever hear from Tidus.