superficially polite but actually rude; rude under a veneer of politeness
Describes a person or behavior that is outwardly courteous but inwardly contemptuous or disrespectful. Often used in formal or critical contexts.
His superficially polite attitude actually made me angry.
慇懃無礼な言い方で断られて、気分を害した。
I was offended when I was refused in a way that was polite on the surface but rude underneath.