[Willow is very, very familiar with humor used to cover up frustration, and uses it frequently herself.]

Oh, she's about to do a spell to-- I mean, I'm about to do a spell to make sure it's all edible. I was just thinking of how to do it. [She's twisted around in her kneeling position on the floor to face him as she speaks, and despite his criticism, she offers him a somewhat apologetic smile.]