Petulantly tells you how someone did a thing: in an unreasonably impatient, rather angry, childish way. They answered petulantly. They slammed the book petulantly. The action itself may be tiny — a word, a look, a door closed too hard — but the manner says “I am not getting what I want, and I will make sure you feel it.” It is a critical word. We use it when we think the person should have been calmer, or older, than they are being. Like petulant, it belongs more to stories and careful English than to the playground, though the behaviour it names is common enough everywhere.

任性地、耍脾氣地