DEAR ABBY: I have been in two relationships. The first was with a girl a couple of years older than I was. We were together for several years before she cheated on me and dumped me. I was crushed. The next girl was a few years younger. She did the same thing after we were together a year. What am I doing wrong? Fidelity is important to me, and they both knew it from the start. How can I avoid this in the future? I have never been a controlling person. I was always fine with my girlfriends going out with their ...