“Whet your appetite,” commonly mistaken as “Wet your appetite”
“Whet” means “to stimulate” so this phrase means to sharpen your desire for something. That doesn’t have to be food, it could be a photo of the Eiffel Tower that “whets your appetite” for a Parisian vacation. The reason people get this wrong: “whet” is an old English word, rarely used outside this expression, whereas “wet” in the context of appetites, conjures the image of a watering mouth, which kinda makes sense, too. Nom nom!