Sex between two adults in a loving relationship is, according to Dr. Ruth, one of the most natural things in the world. And although you don't have to know very much if all you're trying to do is procreate, it's a whole other story if you're trying to get the most pleasure. We're all unique individuals and so the way we get the most out of sex is slightly different for each of us. So in order to engage in sex that maximizes pleasure, some guidelines...