So I was reading my usual
porn blog (NSFW), when I came across this gem of a comment:
Appetites are sharpened by a foretaste, as a knife is sharpened by being ground in the pattern it will cut. To sharpen a knife, one uses a "whetstone", and thus to sharpen it, is to whet it.
This is why one's appetite is whet, not wet.
Who knew porn could be so