dirty linen
dirty laundry

She said black people should not "wash dirty linen in public."

Of course, he thought, no one wants to wash others dirty linen.

They even carried off a bundle of my dirty linen.

There is an old saying: You do not wash your dirty linen in public.

You'll drag out all the family dirty linen into the light of day in the end.

Washing their dirty linen in public like this is something the French seem to do every two or three years.

Even my dirty linen is taken care of by loving hands.

Things can get messy if you air your dirty linen in public.

I don't want to air our dirty linen in public.

"Do you like to wash your dirty linen in public?"