" Give him an inch and hell take a mile "
Meaning:
allow someone a small concession and they will take advantage and try to take more.
Example:
Give Janice and inch and shell take a mile. We said she could stay in the spare room for a couple of nights but she's been here a month already.
Where did it originate?:
USA, 19th century. First seen in the journals of Ralph Waldo Emerson.
Where is it used?:
Hear the idiom spoken: