fair do's

A phrase used when one is emphasizing their belief that something is fair. Come on, you need to watch the kids tonight because I do it all the time—fair do's. Yeah, all right, that's fair do's—you did my chores for me all week, so I'll do yours next week. I didn't tell Mom about that dent is you put in her bumper, so it's fair do's that you keep my bad grade a secret.

fair dos

used to request just treatment or to accept that it has been given. British informal