All laundry starts out dirty, that's why it's in the laundry. Everyone knows the clothes out on a family's laundry line were once dirty, most-likely smelly and there were probably stains. But once it's been cleaned,we aren't embarrassed to hang it in the sun (SON). Hiding our laundry just makes it stink more and the stains increasingly difficult to remove.
It's not helpful when Christians hide other Christians problems, mistakes, sins...... neither is it our right to air out others laundry publicly, dirty or clean. But we shouldn't encourage them to hide it, even if it might make us uncomfortable somehow. We should encourage them to do their laundry. Encourage them to make right with God, so that when other people discover someones laundry, they will also see the forgiving grace of God in their life.
For God sent not his Son into the world to condemn the world; but that the world through him might be saved.
John 3:17