There are a lot of factors that affect it, though. Biology, for instance. How wet does each, individual woman'd pussy get? Genetics: Does a more or less wet pussy run in the family history? Psychology: Is she very freely open about her sexuality or is she cautious and conservative?

All of those factors can affect how wet a woman gets. Also, the frequency of her sex can affect it, as can her amount of orgasms, etc.

Mostly, though, it's just boilogical. Some women get really, really wet and others don't.