put your foot in your mouth
US /pʊt jʊər fʊt ɪn jʊər maʊθ/
UK /pʊt jʊər fʊt ɪn jʊər maʊθ/

1.
失言する, 口を滑らせる
to say something accidentally that embarrasses or offends someone
:
•
I really put my foot in my mouth when I asked her if she was pregnant.
彼女に妊娠しているかと尋ねたとき、本当に失言してしまった。
•
He tends to put his foot in his mouth at family gatherings.
彼は家族の集まりで失言しがちだ。