speak out of turn
US /spiːk aʊt əv tɜːrn/
UK /spiːk aʊt əv tɜːrn/

1.
余計なことを言う, 場違いなことを言う
to say something inappropriate or at the wrong time, especially something that should have been kept secret or that was not one's place to say
:
•
I hope I didn't speak out of turn when I mentioned the new project.
新しいプロジェクトについて言及したとき、余計なことを言わなかったことを願います。
•
He tends to speak out of turn, which often gets him into trouble.
彼は余計なことを言う傾向があり、それがしばしば彼をトラブルに巻き込む。