An attempt at seduction? I don’t believe you! (4-2)
I believe the answer is:
come-on
I believe this clue is a double definition.
'an attempt at seduction?' is the first definition.
(a come-on is a chat-up line)
'i don't believe you' is the second definition.
('come on' may be said to someone in disbelief)
(Other definitions for come-on that I've seen before include "Develop - hurry up!" , "Make progress, thrive" , "Make progress or meet unexpectedly" .)