Tā zhǐshì zài chēng ménmiàn, shíjìshàng yǐjīng pòchǎn le.
He's just keeping up appearances; he's actually already bankrupt.
Tips
usage
门面 has two layers: literal (the physical storefront of a shop) and figurative (maintaining appearances or reputation). 撑门面 (chēng ménmiàn) - to prop up a facade - is a common expression for keeping up a false front.