The most common and most likely answer to this crossword clue is the 6 plus 9 letter word STEADY BOYFRIEND
S
T
E
A
D
Y
B
O
Y
F
R
I
E
N
D
Buddy explains!

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.