you can’t have it both ways
From Longman Dictionary of Contemporary Englishyou can’t have it both waysyou can’t have it both waysCHOOSEused to say that you cannot have the advantages from both of two different possible decisions or actions It’s a choice between the time and the money – you can’t have it both ways! → wayExamples from the Corpusyou can’t have it both ways• It's either me or her. You can't have it both ways!