scratch someone's back

scratch someone's back

Do someone a favor in hopes that a favor will be returned. For example, I don't mind driving this time-she's scratched my back plenty of times. It also is put as you scratch my back and I'll scratch yours, as in If you do the laundry I'll do the cooking-you scratch my back and I'll scratch yours. This idiom was first recorded in 1704.
See also: back, scratch
References in periodicals archive ?
There's almost an unwritten rule in Eurovision that if you scratch someone's back, you'll have yours scratched in return.