clasp an enemy to one’s bosom;regard the enemy as kith and kin;take the foe for one’s father
❍ 甚至有姓爱新觉罗的劝我不要～，要顾惜中国人的尊严。(爱新觉罗·溥仪《我的前半生》284)There was one from a member of my own Aisin-Gioro clan who begged me not to “acknowlege a bandit as my father” and advised me to value my reputation in Chinese eyes.
❍ 所以他们才跪在敌人面前，翻云覆雨，～的。(杨植霖《王若飞在狱中》92) That is why they have prostrated themselves before the enemy and trea cherously accepted the thieves as their own fathers.
认贼作父
take one’s enemy (or the foe) as one’s father;regard one’s foe as kith and kin;go over to the enemy and serve him abjectly
认贼作父rèn zéi zuò fù
认贼人为亲人。比喻把坏人当成亲人，也比喻把妄想当成真实。take the foe for one’s father, regard the enemy as kith and kin