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

1.
daj spokój, przestań
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?
Och, daj spokój, chyba w to naprawdę nie wierzysz, prawda?
•
Come off it, you know that's not true.
Daj spokój, wiesz, że to nieprawda.