fall flat on your face
US /fɔl flæt ɑn jʊər feɪs/
UK /fɔl flæt ɑn jʊər feɪs/
1.
to fail completely or to be unsuccessful in an embarrassing way
:
•
His grand plan to impress the boss fell flat on its face.
•
The comedian's new jokes fell flat on their face with the audience.