First, thanks for the pick and upvotes. Much appreciated.
The candle that whisper secret when blown out, with my limited command in Engrish, I can easily vomit out 2 explanations.
Serious stuff: when a candle is burning, spectator would focus way too much on the lights and heat it generated. Often a scented candle would make great ambient smell, until the moment it was blown out. The incomplete burning smoke would smell way chemical than the scent. We can pretend the horrible smell is not there by walking away, but deep in our heart we all know there's a dirty little secret horrible smell when you try to kill the scented candle and save it for the next occasion.
Not so serious stuff: candle can't whisper secret. The secret is there but we don't see it when one is blinded by the brightness of the candle lights. Until it's blown off, only then you realized there's a pack of wolves starring at you!
I'd try to mischief, but the title seems a little too serious for me 🤣