fast and loose

Not straightforward or honest. “Fast and Loose” was the medieval equivalent of the kind of con game now found in such scams as Three Card Monte. It involved two intricately arranged cloth straps. The victim was invited to choose one loop to place a stick through, and when the loop was pulled tight, the stick would be held fast and the victim would win a wager. However, the con artist had arranged both loops in such a way that either loop came free from the stick, no matter which one the victim selected, and the victim forfeited his bet. (Variations of the game under different names continue to this day.) That's how the phrase “to play fast and loose,” meaning dishonest, came to be used by people who never played the “game.”