[She had noticed his umbrella, but Kath was raised not to impose on other people if she could at all avoid it. But now that he's making jokes about it, she'll dip her chin and lift an eyebrow at him, a smile crossing her face.]

A shame when a girl's got to ask for some aid when it's pouring cats and dogs outside. [It should be obvious enough by her expression, though, that she doesn't mean it in the slightest.]

Do you happen to be offering, professor?