Besetting sin humorous noun phrase
A particular weakness or bad feature
She was so deeply in love with him that she is blind to his besetting sin.
Impatience is my besetting sin.
Used to describe a situation in which people criticize and blame someone else for a fault, mistake or weakness that they also have themselves
The origin of this phrase is not clear.
Used to to emphasize that attention is paid to the individuals who complain or cause problems
Sometimes, you shouldn't be so quiet because the squeaky wheel gets the grease.