What is the origin of the idiom "charm the pants off someone" and when to use it?

The exact origin of the phrase "charm the pants off someone" is not clear, but it is believed to have originated in the United States in the early 20th century. The phrase "charm" is used to describe the act of winning someone over with one's charisma or charm, while "pants off" is used to indicate the success of this endeavor, implying that the person has been so charmed that they have been won over completely. The phrase has since evolved to mean charming or winning over someone in any context, not just in a romantic or seductive way.