thin lips speak freely
It is a Chinese idiom, Pinyin is B á och ú NQ ī ngy á n, which means to describe talkative and casual. It's from Lingshu, Lushun, FeiShou.
The origin of Idioms
In the spring and Autumn Annals, Wu Mingshi's "Lingshu · Fushun fat and thin chapter": "thin people have thin skin, few colors, cheap meat, and thin lips."
Analysis of Idioms
Synonym: talkative antonym: taciturn
Idiom usage
It refers to people who are talkative
thin lips speak freely
with branches profusely covered with leaves - zhī yè fú shū
the country is prosperous and the people are at peace - guó fù mín ān