Any of the normal variables (sitting, usual diner interactions), don't break from him his loop.

Fourth wall questions have him pause and look, not at her, but just past her and static come from this mouth with a few spare words bleeding through: "captain" and "wine".

When she grabs his arm, he freezes and is stock still for a long moment before he sings in a bare whisper:

"....in the master's....gathered for the feast...."