Reveal the Parisian fashion (3,2)
I believe the answer is:
let on
'reveal' is the definition.
('let on' can be a synonym of 'reveal')
'the parisian fashion' is the wordplay.
'the parisian' becomes 'le' (definite article in French).
'fashion' becomes 'ton' (I've seen this before).
'le'+'ton'='LET ON'
(Other definitions for let on that I've seen before include "Reveal information" , "Permitted to board" , "Pretend, feign" , "Tell me" , "give the game away" .)