petulant
pet-u-lant
adjective
Displaying childish bad temper, especially when annoyed by something trivial.
"His petulant outburst over the spilled tea was embarrassing."
Thesaurus
Synonyms: techy, tetchy, scratchy, fractious, peckish, peevish, irritable, testy, cranky, ill-natured, nettlesome, pettish