A government policy that is regarded as particularly petty. The phrase was first applied to tense relations between England and France at the end of the 19th century. How long do we have to suffer under this policy of pin pricks before they finally repeal it?

Telling the truth is always the best course of action, even when being dishonest would be easier or more useful. I think you should just explain what happened, rather than trying to cover your tracks. Honesty is the best policy, after all. Secrets like that will always find their way to the surface, so honesty is definitely the best policy.