spare someone's blushes
US /sper ˈsʌm.wʌnz ˈblʌʃ.ɪz/
UK /sper ˈsʌm.wʌnz ˈblʌʃ.ɪz/

1.
免除某人的难堪, 不让某人脸红
to avoid embarrassing someone or making them feel ashamed
:
•
I decided not to mention his mistake, to spare his blushes.
我决定不提他的错误,以免他难堪。
•
The teacher changed the subject to spare the student's blushes after he gave a wrong answer.
学生答错后,老师换了个话题,以免学生难堪。