air dirty linen in public

air one's dirty linen in public

 and wash one's dirty linen in public
Fig. to discuss private or embarrassing matters in public, especially when quarreling. (This linen refers to sheets and tablecloths or other soiled cloth.) They are arguing again. Why must they always air their dirty linen in public? She will talk to anyone about her problems. Why does she wash her dirty linen in public?
See also: air, dirty, linen, public