The most common and most likely answer to this crossword clue is the 8 letter word WORRYING
I've seen this crossword clue in Financial Times
W
O
R
R
Y
I
N
G
More clues leading to the result WORRYING
Buddy explains!

The straight part
We know that "getting in a fluste" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case getting in a fluste = worrying.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 WORRYING mean?
WORRYING verb- To be troubled; to give way to mental anxiety or doubt.
- Disturb the peace of mind of; afflict with mental agitation or distress.
- To harass; to irritate or distress.
- To seize or shake by the throat, especially of a dog or wolf.
- To touch repeatedly, to fiddle with.
- To strangle.
- Inducing worry.
- The act of worrying or harassing somebody.