Jim: Why? I thought you loved the voices. Ruby: We're big girls now. Jim: Oh. That's right. You're big girls now. That's okay. Well, you're big enough now to check under your beds yourself for the monsters, then, right? Both: We're little girls! We're little girls!
Ruby and Gracie didn't want Jim to read the book with his different voices and Jim knew how to put them back in their place.