What does the word "petulantly" mean as it is used in paragraph 10 of "The Necklace"?

If someone is behaving
petulantly, then they are being somewhat rude in their speech or
actions, and they might even be in a rather peevish and petty mood that could not have been
predicted. When Madame Loisel is described as behaving petulantly, this is exactly what she is
doing. Though her husband has gone to great lengths to procure an invitation to a special party
at the home of the Minister of Education, Madame Loisel is ungrateful. She acts
childishlyquite peevishlywhen she flings the invitation across the table.
Monsieur Loisel expected her to be delighted with the invitation, as she has always imagined
herself to be meant for a life of luxury and ease, and so her mood is unpredictably and
impulsively petty and dissatisfied.