What is the origin of the idiom "spare one's blushes" and when to use it?

The origin of the idiom "spare one's blushes" can be traced back to the 16th century in English literature. The word "blush" refers to the reddening of the face due to embarrassment or shame. The idiom "spare one's blushes" emerged as a figurative expression to describe an act of mercy or kindness shown to someone by preventing them from experiencing such embarrassment. It can also be used in formal settings, such as a professional presentation or public speaking event, where a supportive audience or facilitator may provide assistance or understanding to prevent the speaker from feeling embarrassed.