Possibly related: many Chinese households have a statue of a god in their kitchen. The Kitchen God (named Zao Jun, Zao Shen, Zao kimjah, Cokimjah, or Zhang Lan depending on how you romanize it) is said to report the household's activities to the Jade Emperor just before the lunar new year. As such, to improve his report, you're supposed to smear honey on the statue's lips that day.
honey-lipped
An expression used to compliment someone that says sweet things. 小嘴真甜 (your mouth is so sweet) is also used similarly.
Nowadays used more as sarcasms when someone is spitting shit or nonsense. Also used in a more comedic way in "mean-but-hilarious" situations or even as a support for the person acting mean when the "victim" deserves it.