1. The situation seems to have resolved itself, and I’m not going to bring it up again. I’m going to let sleeping dogs lie
2. The politician resigned his office before his colleagues could bring charges of misconduct against him. After that, they let sleeping dogs lie and didn’t pursue the matter.

Synonym: leave well enough alone. The expression is from a proverb dating back to the 13th century and suggests the threat of attack to one who frightens a dog by suddenly waking it from its sleep.