Aziraphale looks up at him, considering it all for a moment. He's still thinking No, still thinking this is...something he wouldn't do, but looking at Crowley's face, hearing how he asks. Considering how he wouldn't expect the demon to want to do something like this.

...who would ever know, but the strangers that aren't aware a demon and an angel are dancing in a karaoke bar somewhere in Japan?

He smiles fondly, remembering ball-dances from centuries ago. "Oh, fine." He stands.