Q: What gets wet as it dries?
A: A woman with xerophilia!
Theoretically speaking, xerophilia would be an abnormal (probably erotic) interest in dryness and desiccation. Practically speaking, xerophilia would be the only fetish for which I've been unable to find anything. However, considering that real and total dryness is fairly impossible with living humans beings, and that dryness is a very hard thing to convey visually, it doesn't seem too strange that "dry freaks" aren't very prominent. Or maybe they are, and I haven't seen them yet. At the time of writing, danbooru has only three images tagged as "dry", none of which seem very xerophilic. Perhaps this will change when we get holodecks and a tactile Internet, but as for now (2010) xerophilia does not seem very viable.
Now if we can get our minds out of the gutter, we can also say that xerophilic plants exhibit a great affinity for dry climates, xerophilic people exhibit a great affinity for dry humor, and xerophilic people who do not understand Greek word roots exhibit a great affinity for photocopying things.
(note: the joke that opens this writeup was made by forum user rom_maniac)