From Longman Dictionary of Contemporary Englishspeak/talk out of turnspeak/talk out of turnOFFENDto say something you should not say in a particular situation, especially because you do not have enough authority to say it I’m sorry if I spoke out of turn, Major Karr. → turn
Examples from the Corpus
speak/talk out of turn• He enjoys talking out of turn.• Captain Steve Waugh had sharp words with Buchanan, telling him he had spoken out of turn.• Also this week: Ben and Mandy talk out of turn while Luke is listening.• I hope I'm not speaking out of turn, but I don't think this is the best way to proceed. 