The most common and most likely answer to this crossword clue is the 4 plus 3 letter word FAUX PAS
I've seen this crossword clue in Financial Times
F
A
U
X
P
A
S
More clues leading to the result FAUX PAS
- Enemy broadcast old man’s blunder
- Blunder made by stepfathers?
- Dad’s following message about you, said in error
- Message about posh idiot’s retracted mistake
- For all to see in message, father’s blunder
- Football people cross supporting United — dad’s mistake
- Adversary mentioned entrance of slug under annual bloomer
- To copy dad’s embrace of United is a mistake
- Spooner’s a long way from the toilet – that’s a mistake!
- Nothing winning about kiss, a second indiscretion
Buddy explains!
The straight part
We know that "mistake" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case mistake = faux pas.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.