It's tempting to admonish her for calling him Grandpa, but he supposes being seventy years old and all he kind of had it coming. Best to not distract from the thing at hand.

"Of course."

Welp. Here we go. He's kind of surprised she's letting him be the one that does this, but that's a point in her favor. If she were trying to fleece him she'd probably do it herself to ensure a specific set of cards she could give a generic tourist reading from -- or at least that's how he assumes the ruse would go.