to suddenly become stern
他抹脸不认人。
He suddenly turned against them.
抹不下脸来
find it difficult to be strict with someone
汉译英翻译词典收录86165条汉英翻译词条，基本涵盖了全部常用中文字词的英语拼写、翻译、音标、读音、用法、例句等，是英语学习的有利工具。