Former spouse sat, revealed (7)
I believe the answer is:
exposed
'revealed' is the definition.
(exposing is a kind of revealing)
'former spouse sat' is the wordplay.
'former spouse' becomes 'ex' (an ex-spouse).
'sat' becomes 'posed' ('pose' can be a synonym of 'sit').
'ex'+'posed'='EXPOSED'
(Other definitions for exposed that I've seen before include "Uncovered, visible" , "Without cover" , "Laid bare" , "vulnerable" , "Deprived of cover" .)