kill someone with kindness
US /kɪl ˈsʌm.wʌn wɪð ˈkaɪnd.nəs/
UK /kɪl ˈsʌm.wʌn wɪð ˈkaɪnd.nəs/

1.
優しさで人を殺す, 優しさで相手を改心させる
to treat someone who is behaving badly to you in a very polite or kind way, so that you make them feel ashamed of their behavior and change it
:
•
Instead of arguing back, she decided to kill him with kindness, offering to help with his project.
言い返す代わりに、彼女は彼のプロジェクトを手伝うことを申し出て、優しさで彼を殺すことにした。
•
My grandmother always taught me to kill them with kindness when someone is rude.
祖母はいつも、誰かが失礼な態度をとったら、優しさで彼らを殺すように教えてくれた。