It's exactly what Vash needs in this moment. He wails for a minute or two. Nearly on the verge of outright screaming, but he's able to hold onto enough control to not do that.

Eventually the wails calm down into sobs which gives way to choked whimpering. His face a right mess by the time he's left gasping for breath. His body unable to spend any more energy on crying. "I'm sorry." He mumbles out between sniffles.