having one's cake and eating it too

Verb

have one's cake and eat it too (third-person singular simple present has one's cake and eats it too, present participle having one's cake and eating it too, simple past had one's cake and ate it too, past participle had one's cake and eaten it too)

1. (idiomatic) To benefit by having two things which are mutually incompatible (such as eating a piece of cake and yet still possessing that piece for future use).
   • It's not possible to get your savings and keep the piggy bank intact. You can't have your cake and eat it too!