The most common and most likely answer to this crossword clue is the 1 plus 6 plus 2 plus 2 plus 5 letter word I SHOULD BE SO LUCKY
I've seen this crossword clue in The Times
I
S
H
O
U
L
D
B
E
S
O
L
U
C
K
Y
More clues leading to the result I SHOULD BE SO LUCKY
Buddy explains!
The straight part
We know that "Pop success/really?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case pop success/really? = i should be so lucky.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.