cuckoo in the nest
喧宾夺主；闯入他人的圈子或活动中
口语·比喻不受欢迎的外来者
英文释义
an unwanted or intrusive person or thing in a place or situation where they do not belong
例句
The new manager felt like a cuckoo in the nest, as the team was already close-knit.
典故来源
源于杜鹃鸟（cuckoo）将蛋产在其他鸟巢中，幼鸟会排挤宿主幼鸟的习性。