expression
the doting parent's purse is plundered; the thief caught turns out to be one's own son
Proverb meaning that a parent's blind love for their child can lead to their own harm or loss, often used to describe situations where someone is taken advantage of by a loved one.
彼は息子に会社の金を盗まれても訴えなかった。盗人を捕らえて見れば我が子なりだ。
He didn't press charges even when his son stole company money. The thief caught turns out to be one's own son.
A traditional Japanese proverb. The exact origin is uncertain, but it reflects a common theme in folklore about parental blindness.