[There's a numbing comfort in being told "maybe you're right that I shouldn't trust you." It's a welcome reaffirmation of everything he's known for a long time, after all.

Still, even if there's no hope left for him, there is for her. He's sure of that. And if nothing else, he can route himself into helping her, make his existence actually worth something.]

Maybe so. But the way you're acting now, it's something you regret feeling, right? So if it's not something you're proud of, that means it's something you can work to change.

It doesn't make you a horrible person. It just makes you someone with things to work through. And even if I've been a useless big brother... if that's the case, then there's nothing I'd rather do than try to help you through it. It's the least I can offer, in return for all the years you gave to me.

[Hey, both of you? Have you considered that unconditional love is a thing and that neither of you need to earn it?]