a liar and a scoundrel - You call someone a liar and a scoundrel when they tell you t

You call someone a liar and a scoundrel when they tell you the truth, but you're too stubborn to accept it and too much of a mess to care.

She told me I was the one who knocked over the drink, and I called her a liar and a scoundrel because I was too stubborn to admit I was wrong.

He said my dog was in the cereal box, and I called him a liar and a scoundrel because I was too messy to care.

She told me I had a hair in my soup, and I called her a liar and a scoundrel because I was too stubborn to take it out.