Question

mug’s game I told her that spending hours making cakes for few customers is a mug’s game.

Accepted Answer

An unprofitable or ill-advised activity that only a fool (mug) would do is called a mug’s game.

Phrase/Idiom	mug’s game
Definition	An unprofitable or ill-advised activity that only a fool (mug) would do is called a mug’s game.
Example	I told her that spending hours making cakes for few customers is a mug’s game.

Mug’s Game Unprofitable Ill Advised Activity Fool Mug Called