Cover (one's) back American British verb phrase
If you cover your back, you foresee you being accused of or blamed for bad consequences and do something to avoid that.
The boy covered his back by blaming the cat for breaking his mother's favorite vase.
David would do anything to cover his back despite telling lies.
Anne has used a special website for rewriting her friend's essay to cover her back from plagiarism.
Used to describe someone who is naive, gullible, inexperienced, easily fooled, ignorant, unsophisticated, etc.
A harsh reproof
If you offer an excuse regardless of how silly or ridiculous it is, it is more likely that others might accept it than no excuse at all.
To provide the police or authorities with information to expose someone’s wrongdoings
The verb "cover" should be conjugated according to its tense.
A humorous way of saying that what one has said is just what they acknowledge and may not be entirely accurate
Mike: Have you returned from your vacation on the beach? Your skin seems to get tanned.
Jenny: My skin is always dark. That's my story and I'm sticking to it!