The most common and most likely answer to this crossword clue is the 2 plus 3 plus 10 letter word IN THE ALTOGETHER
I've seen this crossword clue in The Guardian
I
N
T
H
E
A
L
T
O
G
E
T
H
E
R
More clues leading to the result IN THE ALTOGETHER
- Wearing but a smile as fitness keeps love secure in Bury
- Going crazy here, late tonight, fully undressed
- Naked, I then hassled singer — what a diva!
- Hitherto elegant model is exposed
- Hitherto, elegant forms exposed
- Naked dancing here, late tonight
- One books male singer: to acquire female as stripper, finally?
Buddy explains!

The straight part
We know that "exposed" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case exposed = in the altogether.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.