恬不知耻的不感到或显示悔恨，羞耻的，毫无歉意的。

Feeling or showing no remorse, shame, or need for apology.

youdao

她恬不知耻地承认了让他回到屋里的事。

She had brazenly admitted allowing him back into the house.

《牛津词典》

他就是我的小我，我的主，他恬不知耻；但和他一同到你门前，我却感到羞愧。

He is my own little self, my Lord, he knows no shame; but I am ashamed to come to thy door in his company.

youdao