bang/knock your/their heads together

knock (people's) heads together

To scold two or more people harshly. If you two do something this stupid again, I'm going to knock your heads together!
See also: head, knock, together

bang/knock your/their ˈheads together

(informal) force people to stop arguing and behave in a sensible way: I’d like to bang those stupid politicians’ heads together.
See also: bang, head, knock, together