to put your foot in it

To put your foot in it means to say or do something embarassing by a mistake

I really put my foot in it when I asked how his wife was - she has just left him for another man!

Gretchen is so tactless - every time she opens her mouth she puts her foot in it!

Legend has it that this expression was coined as a comment on a remark made by the Irish politician, Sir Boyle Roche, who was elected to the Irish Parliament in 1775 and was famous for his mis-use of language.

After one of Roche's comment during a debate that " Half the lies our opponents tell about me are not true", one of his colleagues remarked "Every time he opens his mouth he puts his foot in it!" .... and the saying stuck.

However, Roche continued his colourful use of the language with many memorable phrases such as:

I answer in the affirmative with an emphatic "No"

We should silence anyone who opposes the right to freedom of speech.

While I write this letter, I have a pistol in one hand and a sword in the other.

it has been suggested , in fact, that he used such phrases to confuse and entertain the opposition.