To pretend to be fat by beating one's face

打腫臉充胖子

PinYin: Da3 Zhong3 Lian3 Chong1 Pang4 Zi

Try to satisfy one's vanity when one cannot really afford to do so.

Literally, this slang means to beat one’s face until it’s swollen in an effort to look imposing; metaphorically, it means to do something beyond one’s means.

Example:
自己都快不能吃飯了還要借錢給朋友，何必打腫臉充胖子？
Why are you lending out money to your friends when you can’t even afford to feed yourself?