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

1.
真っ赤な嘘をつく, 平気で嘘をつく
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.
彼はお金がなくなったことについて何も知らないと言ったとき、真っ赤な嘘をついていた。
•
You don't have to lie through your teeth to impress me.
私を感動させるために真っ赤な嘘をつく必要はない。