Steve's mouth twists; he can definitely imagine that if he's trying to explain that someone might need to take him down, Bucky might be thinking the same thing.

He nods; "Yeah. Well - usually just once, but sometimes twice. And sometimes there are breaches. Those are - " Worse? Better? He honestly isn't sure, and ends up settling on, "different. You're definitely not you, then. You're someone else completely." Even though it feels like you've been that person your whole life.

But now they're finally at the point where Steve feels like he's got information he just can't keep withholding from Bucky. Even if this might go badly. So he pauses, regroups, glances up, trying to catch Bucky's eyes. "I know your trigger words. I wish I didn't, but I do." And he can't forget them. He's got a stupid eidetic memory, and he's tried asking people to erase them, and there's always some reason they can't. "No one else does. But - I do. I wanted you to know. Because I will never use them against you. I will never tell anyone else. As long as I'm me. I swear."