get (one's) lines crossed(redirected from get their lines crossed)
get (one's) lines crossed
To have a misunderstanding or miscommunication with someone else. I'm sorry I'm late, I thought we were getting here at 8—we must have gotten our lines crossed. My mom and I got our lines crossed, and now there's no one here to babysit the kids.
get your ˈlines/ˈwires crossed,
have crossed ˈlines/ˈwires(informal) misunderstand each other: I think we’ve got our lines crossed somewhere. I said Venice, not Vienna. ♢ We must have got crossed wires. I thought you were going to drive, not me.
This refers to telephone wires/lines that are not connected properly.