The most common and most likely answer to this crossword clue is the 3 plus 2 letter word OWN UP
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More clues leading to the result OWN UP
- Mature person, hiding the grey, to be honest
- Admit that was painful bit of humour, taken wrong way
- Confess it hurts having wordplay rejected
- Admit it’s a bit limp — unworthy of review
- Admit cry of distress on picking up wordplay
- Admit it hurts to reject groan- worthy joke
- Confess that was painful joke
- Admit adult leaving Greece
- Admit personal period of good fortune
- Admit pained expression greets rise of wordplay
Buddy explains!

The straight part
We know that "Make a clean breast of" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case make a clean breast of = own up.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.