[fā pí qi]
lose one's temper; get angry; cut up rough; let oneself go; hit the ceiling; fly into a temper
Don't lose your temper over such a trifle.
不要为这点小事发脾气。
Speak calmly if you think you're in the right; there's no need to get angry.
有理慢慢儿说,何必发脾气。