lose one's temper , also: lose one's countenance

Each of them in turn lost his or her temper.

If you hadn't lost your temper and killed him, one of us would have.

The first time, in fact, he had ever lost his temper with her.

She should never have lost her temper and said such things to him.

The first person who lost his temper at the other had to pay up.

She would not give him anything else, no matter how often he lost his temper.

My friend here just lost his temper for a moment.

He'd had a long day and he lost his temper.

The military man finally lost his temper, even in the face of one so high.

He couldn't remember the last time he'd lost his temper.