The base nomenclature is useful, but problematic. It implies a competition between two opposing forces and perpetuates a conquest-based view of physical intimacy... and, as such, it is definitely - though I would argue, not inherently - misogynist.

And, of course, it also implies that there is a "right" way to do sex, where one must necessarily progress through mandatory stages in order to reach a specific goal - the only goal that matters. In baseball, one cannot skip over the pitcher's mound to second base, nor can one linger on second base without progressing, inevitably, to third and to home. I, for one, can enjoy getting to second base, decline moving on to third, and end the game without feeling that my time therein has been wasted.

The metaphor is also somewhat muddled when one tries to take the other aspects of baseball into account. Must the romantic partners in question take turns in trying to score points off each other? What, exactly, is one doing when one is at bat, before one gets to first - and what do balls and strikes equate to? What is the romantic equivalent of a foul ball, or stealing a base, or taking a fastball to the side of the head and walking to first?