wouldn't hurt a fly
成語所屬單字hurt
wouldn't hurt a fly — 慣用語
1. used to say that someone is very gentle by nature and would never cause harm to
1.慣用語
釋義
連蒼蠅都不會傷害（形容人非常溫和）
used to say that someone is very gentle by nature and would never cause harm to anyone or anything.
例句
Don't be afraid of the big dog — he wouldn't hurt a fly.
Nia talks tough, but she wouldn't hurt a fly really.