walls have ears

Proverb

There is a risk of being overheard, so be careful about what you say.

Japanese Meaning

壁にも耳あり：誰かに盗み聞きされる可能性があるため、注意深く言葉を選ぶ必要があるという警告の意味。

When discussing the surprise party, remember walls have ears, so keep it quiet.

サプライズパーティーの話をするときは、壁に耳があると思って静かにしましょう。

Sense（1）

There is a risk of being overheard, so be careful about what you say.

But it is well to remember that walls have ears, and therefore to whisper.