Dear Amy: I am a mature 25-year-old college-educated man with a great career. I was on the dating scene for several years when I met “Julie” — the girl of my dreams. We fell deeply in love and after four months we began to speak of a long-term future together. We seemed compatible in all the important ways for a good marriage, and I was happier and more secure with her than with any other woman I ever knew. Julie had just ended a long-term relationship when we met, and one day she told me that this old lover was coming through town and wanted to see her.