What does Pop Goes the Weasel mean?

The phrase "Pop Goes the Weasel” comes from an old parlor game popular in the 19th century. In the game, players would sit in a circle and pass around a small toy weasel. When the music began to play, the player holding the weasel would raise it above their head and exclaim, "Pop goes the weasel!" while trying to pass it on to the player next to them. The player who ended up holding the weasel when the music stopped was out of the game, and the last player standing was declared the winner. The origins of the phrase and the game are unclear, but it is believed the game may have originated in England during the 19th century. The phrase itself is likely derived from the sound made by the toy weasel's head popping out when released. The game was popular in both England and the United States, and the phrase has become a common expression used to refer to something that is surprising or unexpected.