면목 없습니다 (We are ashamed to face you)

면목 [n] A state of mind or position to deal with others without the sting of embarrassment.

informal/casual – 면목없어 

>> This expression is used when a person is so ashamed and sorry for something they said or did to another person that they do not have the courage to face the other person.

>>It is used when the speaker is feeling sorry to the extent that they are embarrassed to show their face because they have caused trouble to the hearer. It is often regardless of whether it is their own mistake or fault, or even the mistake of someone related to them.