lie through your teeth
US /laɪ θruː jʊər tiːθ/
UK /laɪ θruː jʊər tiːθ/

1.
mentir descaradamente, mentir sin pudor
to tell someone something that you know is not true, often in a blatant or unashamed way
:
•
He was lying through his teeth when he said he didn't know anything about the missing money.
Estaba mintiendo descaradamente cuando dijo que no sabía nada del dinero desaparecido.
•
You don't have to lie through your teeth to impress me.
No tienes que mentir descaradamente para impresionarme.