The most common and most likely answer to this crossword clue is the 9 letter word NARRATING
N
A
R
R
A
T
I
N
G
Buddy explains!

The straight part
We know that "telling" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case telling = narrating.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 NARRATING mean?
NARRATING verb- To relate (a story or series of events) in speech or writing.
- To give an account.
- An act of narration.