expression
kindness can backfire; pardon makes offenders
Proverb warning that excessive leniency or kindness may be taken advantage of, leading to harm. Often used when someone's good intentions are repaid with ingratitude or betrayal.
彼を許したのが情けが仇となって、また騙された。
My forgiving him backfired, and I was deceived again.
情けが仇になることもあるから、甘やかしすぎないほうがいい。
Sometimes kindness can backfire, so it's better not to be too indulgent.
A set phrase combining 情け (kindness, compassion) and 仇 (harm, enemy, grudge). The exact origin is uncertain, but it reflects a traditional cautionary view that excessive mercy can lead to one's own misfortune.