養虎為患 [ㄧㄤˇ ㄏㄨˇ ㄨㄟˊ ㄏㄨㄢˋ; yang3 hu3 wei2 huan4] lit. to nurture a tiger invites calamity fig. to indulge one's enemy is asking for trouble (idiom) ◄ ►