petulance

她的任性让所有人都感到疲惫，因为为了一点小事就发脾气。

Her ___petulance exhausted everyone as she threw tantrums over minor issues.

当被告知不能买新玩具时，小男孩跺着脚表现出了任性。

The little boy stomped his feet in ___petulance when told he couldn't buy the new toy.