You can't have it both ways

Meaning

You cannot enjoy two mutually exclusive things at the same time. It is used when someone is trying to cheat the system or avoid making a hard decision.

Firm, logical

Used in a sentence

• You want to save money but never go to work? You can't have it both ways.
• You can't have it both ways, you have to choose between the house and the boat.
• If you want the freedom to travel, you have to accept the long flights; you can't have it both ways.