Okay in all seriousness this should probably go in the sex forum
Don't ever let somebody tell you can't do something. You got a dream... You gotta protect it. People can't do somethin' themselves, they wanna tell you you can't do it. If you want somethin', go get it.
Yer probably for the sex forum, but maybe because you've put it in relationship forum you are interested in talking about the relationship issues causing this problem?
How did you used to make her wet? Was it easy? How long ago did it stop? Are there any medical reasons for this problem? Is she on any type of medication? Or going through any particular changes?
I think it is a common problem, personally i experienced it in the later stages of my relationship with my ex, i suppose the excitement had gone, or if i'm dehydrated. These days i have problems with getting too wet!
Maybe try going down on her, then she'll be wet. Slightly worrying that she needs to pretend you're someone else but whatever it takes to spice up your sex life is a good idea. You could try all the other stuff, sex toys, games etc etc.