Confused at fiancés showing interest (9)
I believe the answer is:
fascinate
'interest' is the definition.
(fascinating is a kind of interesting)
'confused at fiances' is the wordplay.
'confused' indicates anagramming the letters.
'at'+'fiances'='atfiances'
'atfiances' with letters rearranged gives 'FASCINATE'.
'showing' acts as a link.
(Other definitions for fascinate that I've seen before include "Captivate" , "Enchant - beguile" , "Irresistibly interest" , "Charm" , "Intrigue" .)