[She doesn't refuse the hand, but she makes no effort to make it easier to take either. She sighs and...]

Have to. Proper. What, so you'd just tell me now and then that would be that? Not even breaking up, just vanishing after giving me two sentences notice? Don't screw with me.

[She sighs. No. No, the obvious thing is that it won't work. Winry "has to" believe in them, so she doesn't have honest confidence]

...If this fails, you owe me.