They are alike, in too many ways, and Tony hates him for it. Because Odin has given Loki more love than Howard Stark ever gave Tony, and he didn't turn out to be a glory hungry psychopath. But he also knows that affection is not approval, and damn it all if he understands. He doesn't know where he'd be, either, if he hadn't stopped caring about trying to make his father proud long before he died. Tony does what he does for himself, no one else. Loki does what he does to please a man who punishes his children for his own failure as a father. Tony gets it, and he doesn't want to, and he hates Loki all the more for it.
They are alike, in too many ways, and Loki hates him for it. Because if Tony Stark lacks the approval of his father, then at least he has success. Loki has neither of these things. But if he feels the tendrils of a jealous seed close in around his heart, he denies it. The man is mortal, ignorant. A fool. And he knows too, that success hasn't been enough. Stark holds the world on a silver platter, but he is unhappy, and it hasn't healed the gaping wounds his father left. Loki is like him. His heart is hewn open and emptied, but he needs to believe that something can fill it. And Stark, Stark, he is the embodiment of the failure of this dream, and he hates him all the more for it. But he denies the truth his soul knows, and keeps on chasing empty dreams. The Liesmith must lie to everyone, if even to himself.
They are alike, in too many ways, and maybe this is why Tony did not turn him away the first night he appeared to him, stepping out from that celestial light. Nor the second time, nor the third, nor the many after that. They let themselves be seduced, feel the comfort of knowing another person's body, of knowing eachother.
I hate you, they say with their words. You are the antithesis of all that must be.
I know you, they say with their mouths, and their tongues, and their flesh. We are the same, and I hate what your existence means to me.
I hate you, they say, neither one quite meaning the words. But it does not deter them as it tumbles from their lips. They both know what they really mean, and they steep in the relief of being intimately, infinitely, wordlessly understood. Here, they can finally breathe.