Men are always on the lookout for an easy way to get a read on women. Some men like to brag about how they can tell whether a woman is any good in the sack simply by watching the way that she walks away from them. For the most part, this is just a bunch of malarkey (Though here and there, statistically speaking, you will run into the real McCoy, a veritable vaginal Nostradamus. These guys are few and far between, but they do exist!) In any case, there really aren't too many tried and true methods for predicting a girl's behavior in the sack. One that is fairly reliable though, and seemingly counter-intuitve on the surface, is the old sexy librarian. You know the type: looks straight-laced, wears conservative skirts, enjoys reading massive stacks of books, has pair of glasses perched perfectly on the bridge of her nose. These girls, as it turns out, only look conservative. Almost every one of them is secretly harboring a hankering for a robust and lengthy fucking which ends in a spray of semen crossing their glasses!