You use bare-faced to describe someone's behaviour when you want to emphasize that they do not care that they are behaving wrongly.
例句
What bare-faced cheek!真是厚颜无耻！...crooked politicians who tell bare-faced lies.满嘴无耻谎言的奸诈政客
英英词典释义
Adjective
1. with no effort to conceal;
"a barefaced lie"
2. unrestrained by convention or propriety;
"an audacious trick to pull""a barefaced hypocrite""the most bodacious display of tourism this side of Anaheim"- Los Angeles Times"bold-faced lies""brazen arrogance""the modern world with its quick material successes and insolent belief in the boundless possibilities of progress"- Bertrand Russell