Bucky swallows hard, because Steve has a point. Without Bucky there to keep the heat on, and even then, what were the chances that something else didn't come up? Steve's health has always been so fragile, and more than once he'd rushed home because Steve was in a particularly bad way...

"Where are you goin', punk?" he asks as soon as it's obvious Steve's about to leave. Like he's going to let him do that now. They're still alone, and it's not like any of the guys are going to show up when Bucky had walked off with the guy they'd been heckling moments before.