"Oh."

For a long time that's the only noise out of his mouth, lips seemingly frozen in that little O shape as surprise spreads across his face. But inside, things are far from frozen. Aside from the shock, there also seems to be a fireworks display going off in his stomach, swooping and blossoming in delight, though it's tinged with a small amount of annoyance.

Eventually he shakes himself out of it and reaches out to slap Steve across the back of the head, like Sarah used to do to her son and to Bucky when they were being naughty.

"What the hell? Why didn't you tell me? You're such a goddamn asshole."

He cut off his own anger by leaning in and following up that slap with a sudden and brief kiss to the lips, reckless in abandon now that he knows the truth.

"I've loved you since the moment I met you, but you never said anything when you came out so I figured you didn't like me."