have one's cake and eat it too
- (idiomatic) To seek to have 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!
- This expression is found almost exclusively in some form of the saying or proverb: You cannot have your cake and eat it too.
to seek to have two things which are mutually incompatible