on someone's back

on someone's back

Also, on someone's case. See under off someone's back.
See also: back, on

on someone's back

If someone is on your back, they are criticizing you a lot or trying to persuade you to do something. The crowd aren't forgiving — as soon as you make a mistake they're on your back. If they find out you're weak, they're on your back straight away. Compare with get off someone's back.
See also: back, on