"grin from ear to ear" in Chinese (Simplified)
笑得合不拢嘴
Definition
露出非常开心、灿烂的笑容，表示你非常高兴或激动。
Usage Notes (Chinese (Simplified))
属于口语表达，形容人因高兴而满脸笑容，常用于形容听到好消息或成功时的反应。只用于人，不用于物品。
Examples
She grinned from ear to ear when she got the job.
她得到工作时，**笑得合不拢嘴**。
The boy grinned from ear to ear after winning the race.
男孩赢了比赛后，**笑得合不拢嘴**。
They grinned from ear to ear in the family photo.
他们在全家福里**笑得合不拢嘴**。
When he saw his surprise party, he just grinned from ear to ear.
看到惊喜派对时，他直接**笑得合不拢嘴**。
You should have seen her; she was grinning from ear to ear after the meeting.
你应该看到她，开完会后她**笑得合不拢嘴**。
He walked into the room grinning from ear to ear like he'd just won the lottery.
他走进房间时**笑得合不拢嘴**，好像中了大奖。