Romantic deception involved no therapy (5,4)
I believe the answer is:
honey trap
'romantic deception' is the definition.
I know nothing about this answer so I can't tell whether this works.
'involved no therapy' is the wordplay.
'involved' indicates anagramming the letters (involved can mean confusing or complex).
'no'+'therapy'='notherapy'
'notherapy' anagrammed gives 'HONEY-TRAP'.
Can you help me to learn more?
(Other definitions for honey trap that I've seen before include "sexual enticement" , "Charming stratagem" .)