[Armin returns her gaze in kind. It's clear from his expression that he has to consider the question, but he's not exactly surprised by it.

[Is Eren his responsibility? Their responsibility? That's never been the reason they've gone after him. Sure, at some point, they had been responsible for keeping him safe. His powers were invaluable; of course they had to keep him safe. But even if that hadn't been the case, Armin would have done anything in his power to protect Eren - he still would. Not because Eren is his responsibility, but because...]

Eren is my friend. There's a certain level of responsibility that comes with that, don't you think?

It's not as if I feel I have to be his keeper, or anything like that. But I want to help him. I want to do whatever I can for him, because...well, I...

[He bites down on his lip a little, chewing anxiously, momentarily averting eye contact.]

I love him.

[Another brief moment of silence passes. Armin frowns, letting his mouth quirk to one side.]

But...although Eren might not be my responsibility, saving the world from total annihilation...? I'd expect anyone to step up in that case.