The most common and most likely answer to this crossword clue is the 13 letter word TITTLE-TATTLE
I've seen this crossword clue in The Guardian
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More clues leading to the result TITTLE-TATTLE
Buddy explains!
The straight part
We know that "Gossip in front of both petite and neat topless model (6-6)/Gossip" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case gossip in front of both petite and neat topless model (6-6)/gossip = tittle-tattle.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.
What does TITTLE-TATTLE mean?
TITTLE-TATTLE noun- Petty, idle gossip.
- An idle, trifling talker; a gossip.
- To engage in such gossip.
- To spread gossip.