Writer over marriage heartlessly admitted to affair (7)
I believe the answer is:
fleming
'writer' is the definition.
Both the definition and answer are singular nouns.
Maybe there's an association between them I don't understand?
'over marriage heartlessly admitted to affair' is the wordplay.
'over' is a reversal indicator.
'heartlessly' suggests removing the centre.
'admitted to' means one lot of letters goes inside another.
'affair' becomes 'fling' (a fling is a romantic affair).
'marriage' with its centre taken out is 'me'.
'me' written backwards gives 'em'.
'em' put within 'fling' is 'FLEMING'.
Can you help me to learn more?
(Other definitions for fleming that I've seen before include "Belgian < novelist" , "Native of Flanders" , "Ian -, Bond author" .)