He's sure he didn't just hear what he thought he did. Bucky. Not dead. His brain is short-circuiting, eyes glazing over as Cap goes on, and on. The multiple mentions of his father and Peggy punch him right in the gut, knowing he was blissfully going about his adolescence without the faintest clue that this was lurking just under the surface. Well, alright, maybe not blissfully, but he was ignorant to all of it because that's how Howard wanted it to be.
Bucky is alive. Bucky is a super-soldier. Bucky is the man with the metal arm that almost killed his friends (and some guy named Sam.) He opens his mouth and closes it a few times, doing his best imitation of the fish guppying about just beyond their bedframe. He can't feel his extremities; an eerie numbness settling over him in the wake of Steve's panicked revelation.
"You know that doesn't change anything I said." It's soft, his voice tight with barely kept emotion. "How was I supposed to know..." He wasn't and he didn't, but he can still fix this. Somehow -- he doesn't fucking know how okay, but he didn't know how to save himself or the Avengers and he did both. When the time comes, he always turns it out. "You really weren't going to tell me any of this."
And that, too, hits him like a blow. Without the duress of magic poppies or whatever the fuck, Steve would never have bothered with this conversation. Because it was too grim, Tony supposes. He knows he can't exactly get indignant, he is the guy who couldn't tell his girlfriend he was dying. Anger isn't going to help here, so he shoves it away. It's disturbing how easy it is to dismiss, really. But he's used to being betrayed, just like Steve is used to being chewed up and used by those closest to him. He'll get over it. What matters is what happens next, here. Between them.
"I just. Give me a minute to..." Tony pinches the bridge of his nose and sighs, emulating Bruce without even realizing it. He could really use some of the other scientist's zen right now. "I'm sorry? Is that what I say here. I mean, that that happened to you. That I couldn't be there. That I didn't know." There are so many things to be sorry for, but no real point to it in the end.
"You're sure my father didn't know?" He would never say anything slanderous against Peggy, even if where one went the other followed. He still values his teeth even in this sitch tho. "He never told me anything. About S.H.I.E.L.D. About his real work. I don't even think my mother knew." But Tony can't be sure this is beyond Howard, no matter what he said on that video that saved his life. He barely even knew the guy.