Turn a blind eye

Brief Definition: 
To look away as if you did not see what you really saw.
Further Explanation: 
Usually used to describe someone ignoring something that they really saw (possibly something wrong or illegal). Most of the time, it has a negative connotation but does not always. See the examples below.
Examples: 
The neighborhood children were stealing from the apple orchard. The owner turned a blind eye because he knew they were poor and hungry.
The woman saw her co-worker, Nini, take money from the petty cash drawer. She turned a blind eye because she knew Nini had not told their boss about her many times being late for work.
Many apartment dwellers wish their dog-owning neighbors would do the responsible thing and clean up their dogs’ messes. However, many just turn a blind eye to this selfishness in order to keep peace in the community.
Idiom Ratings
Popularity (Scale 1 to 5): 
3
Formality (Scale 1 to 5): 
5