口くちを合あわせる

expression, ichidan verb

get one's story straight; coordinate what to say

Used when people agree on a version of events beforehand so their accounts match. Often implies a deliberate effort to avoid contradictions, sometimes with a negative connotation of collusion.

See also: 口裏を合わせる

• 警けい察さつに話はなす前まえに、みんなで口くちを合あわせた。

  Before talking to the police, they all got their stories straight.

• 彼かれらは口くちを合あわせて同おなじ嘘うそをついた。

  They coordinated their stories and told the same lie.