fall flat on your face
US /fɔl flæt ɑn jʊər feɪs/
UK /fɔl flæt ɑn jʊər feɪs/

1.
徹底失敗, 栽跟頭
to fail completely or to be unsuccessful in an embarrassing way
:
•
His grand plan to impress the boss fell flat on its face.
他想給老闆留下深刻印象的宏偉計劃徹底失敗了。
•
The comedian's new jokes fell flat on their face with the audience.
這位喜劇演員的新笑話在觀眾面前徹底失敗了。