Lover — fire (5)
I believe the answer is:
I believe this clue is a double definition.
'lover' is the first definition.
(I've seen this before)
'fire' is the second definition.
(Other definitions for flame that I've seen before include "Evidence of fire" , "Send a rude message" , "Sweetheart" , "object of one's affection" , "abusive comment" .)