Is your longest-running relationship with the guy who pumps your gas? Are the women on those talk shows who date "men behind bars" starting to make sense? Do the men in your life seem to come with a 10-day expiration date? If so, chances are you already know how to lose a guy. You probably just don't know how you're doing it. Here are some clues: Start calling him your boyfriend by the next day. In fact, just call him. Call him again. Don't forget to make him mix a tape with all of "your" songs....