In each affair, there's badinage (5)
I believe the answer is:
chaff
'badinage' is the definition.
(I've seen this in another clue)
'in each affair there's' is the wordplay.
'in' indicates a hidden word.
'CHAFF' can be found hidden inside 'each affair theres'.
(Other definitions for chaff that I've seen before include "Refuse - banter" , "Light banter - husks from corn" , "Tease in good-humoured way" , "Rubbish" , "Corn husks - worthless stuff" .)