Explanation

"You can't have your cake and eat it too".

آپ اپنا کیک نہیں کھا سکتے اور اسے بھی کھا سکتے ہیں۔

It means that you can't enjoy the benefits of two things that are mutually exclusive.

It's a idiomatic expression that suggests you can't have two things that don't go together.