Least said soonest mended
Definition 1 of 1
Pro Tip 1/3Conflict Avoidance
Used to prevent arguments or worsening situations by staying quiet. 
They were starting to argue, so he remembered 'least said soonest mended' and changed the subject.
Pro Tip 2/3Move On Quickly
Helps suggest focusing on solutions rather than discussing the problem further. 
I know I was wrong, but least said soonest mended. What's the next step?
Pro Tip 3/3Regret Minimization
Implies that talking less about a mishap can reduce feelings of regret or embarrassment. 
After the awkward moment, she thought 'least said soonest mended' and stayed quiet.