The bounce in your step coupled with the immediate desire to help someone out without any consideration as to whether or not they wanted it perhaps?

[ Vanitas can only respond with a semi lazy smirk at that. OR! Maybe that's all part of her game? He doubts it for some reason. ]

Though technically there is a "graver threat" isn't there? They can't possibly believe that just because they live under the surface of the planet that what happens above can't also effect this place.