After ending a painful five-year affair, author Casey Clair came to the surprising realization that being married isn't the only way potential partners make themselves unavailable. In fact, men and women can be emotionally, legally, and sexually unavailable for happy, healthy relationships in dozens of ways. Casey Clair's new book, "Still Single: Are You Making Yourself Unavailable When You Don't Want to Be?," is filled with startling revelations...