The most common and most likely answer to this crossword clue is the 5 plus 1 plus 4 letter word STEAL A KISS
I've seen this crossword clue in Financial Times
S
T
E
A
L
A
K
I
S
S
Buddy explains!
The straight part
We know that "Grab an affectionate moment" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case grab an affectionate moment = steal a kiss.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.