shoot your mouth off

US /ʃuːt jʊər maʊθ ɔːf/
UK /ʃuːt jʊər maʊθ ɔːf/
"shoot your mouth off" picture
1.

puszczać parę z ust, gadać za dużo

to talk too much, especially in a boastful or indiscreet way

:
He tends to shoot his mouth off after a few drinks.
Ma tendencję do puszczania pary z ust po kilku drinkach.
Don't shoot your mouth off about the surprise party.
Nie puszczaj pary z ust na temat imprezy niespodzianki.