speak too soon
US /spiːk tuː suːn/
UK /spiːk tuː suːn/

1.
早とちりする, 時期尚早に言う
to say something that turns out to be wrong very soon after you have said it
:
•
I thought I had finished all my work, but I guess I spoke too soon.
すべての仕事を終えたと思ったが、どうやら早とちりだったようだ。
•
The baby finally fell asleep. Oh, wait, I spoke too soon, he's crying again.
赤ちゃんはついに眠りについた。ああ、待って、早とちりだった、また泣いている。