come off it
US /kʌm ɔf ɪt/
UK /kʌm ɔf ɪt/

1.
arrête tes bêtises, cesse
used to tell someone that you do not believe what they are saying, or that you disagree with it
:
•
Oh, come off it, you don't really believe that, do you?
Oh, arrête tes bêtises, tu ne crois pas vraiment ça, n'est-ce pas ?
•
Come off it, you know that's not true.
Arrête tes bêtises, tu sais que ce n'est pas vrai.