In chapter 4, why were Mrs What is and Mrs Who giggling?

I believe the women are laughing at their disarray, as they appeared to the children. The text alludes to a "private joke" between the women.... Calvin responds to their laughter in the following way... " If you ladies have had your fun...". I don't think there's any hidden meaning here. It's simply the lack of orentation after tessering, not to mention the children still haven't seen the women's true forms.