Did you seriously teach her a waltz, or did she just know that when you asked? [He's thankful it's a slow tune, because does anyone want to take a guess how long it's been since Church has done any slow dancing? Any takers? Any? He doesn't trip up, but he does shut up a bit to pay attention, following after...not nearly so smoothly, but following after.]

Which implies you asked, either way, at some point.