to speak out of turn

• 多嘴多舌

  loose-tongued

• 她原来爱多嘴。

  She has always loved to talk.

• 你不了解情况，就别多嘴。

  You don't understand the situation, so keep quiet!

• 您这是公事，我可不敢随便多嘴！

  This is official business – I wouldn't dare to speak out of turn!