talk out (the side of) one’s neck
v. phr.— «Inside the prison, there is Jimmie’s mentor Virgil Cane, played by F. Murray Abraham, who throws himself rather too heartily into the screenplay’s enthusiastic jive (’‘Hey! Don’t you be talkin’ out the side of your neck when I’m tryin’ to do you a solid!’‘).» —“Tom Selleck as a Police Pawn, in ‘Innocent Man’” by Janet Maslin New York Times Oct. 6, 1989. (source: Double-Tongued Dictionary)