Country where father takes part in vice (5)
I believe the answer is:
spain
'country' is the definition.
(I know that Spain is an country)
'father takes part in vice' is the wordplay.
'father' becomes 'pa' (pa can mean dad or father).
'takes part in' means one lot of letters goes inside another.
'vice' becomes 'sin'.
'pa' inserted into 'sin' is 'SPAIN'.
'where' acts as a link.
(Other definitions for spain that I've seen before include "EU country" , "It pains one to be out in this country" , "Country bordering Andorra" , "European monarchy" , "Crazy pains?" .)