打肿脸充胖子

dǎ zhǒng liǎn chōng pàngzi

(1) [quff oneself up to one's cost; to slap one's face until it's swollen in an effort to look imposing]∶夸大自己的能力

(2) [do sth. beyond one's ability]∶要面子, 硬撑着做力不能及的事