expression, godan verb (-ru)
hide one's true self; feign friendliness; play the hypocrite
Idiomatic expression meaning to put on a false front, pretending to be nicer or more innocent than one really is. Often used when someone is hiding their real intentions or personality.
See also: 猫をかぶる (ねこをかぶる)
彼は上司の前ではいつも皮を被っている。
He always puts on a good face in front of his boss.
That kid is good at acting innocent in front of their parents.