Chhota munh badi baat : a small mouth, big words. The Rekhta dictionary gives its Hindi meanings as speaking above one’s ability, claiming more than one has been encouraged to, and badon ke samne dhrishtata dikhana, showing impudence in front of elders.
Gustakhi maaf : “pardon (my) rudeness, excuse me,” in Rekhta’s definition. Rekhta notes that the related phrase gustakhi muaf ho is used as an aside when someone says something impolite or unwelcome.