DEAR ABBY: I met “Guy” seven years ago and fell deeply in love. We dated for a couple of months, but one day with no warning he broke up with me on my voicemail.

Three weeks after the breakup, Guy came to my home. It was the week of his wedding, which he never bothered to mention. I later heard he had been married from a mutual friend. I knew Guy had been seeing someone, but he never indicated that it was serious.

We have been having an affair ever since our breakup. Because I love him, I can’t say no to him. He’ll go through periods where he says he’s getting divorced. He even told my mom that. Then he calls and says they’re going to work it out. I never pushed. I want him to be happy — even if it’s not with me — and I want no part in causing a divorce. Every time I start to get over Guy, he comes around again. It’s like he has radar.

The last time we slept together, a month ago, he told me he thought he had married the wrong woman. The next day, he admitted he has too much at stake to make a change. I am in so much pain. I don’t want to be his mistress. If I tell his wife, Guy will never speak to me again. Should I tell her? — RUNNER-UP IN CHEYENNE

DEAR RUNNER-UP: Whether you’re willing to admit it to yourself or not, by continuing the affair with Guy you HAVE been trying to sabotage his marriage. Your first clue that Guy wasn’t much of a man should have been when he used voicemail to “break up” seven years ago. He has now made it plain that he isn’t going to leave his wife.

Haven’t you recognized by now that he is concerned only with his own gratification and doesn’t care who is hurt by his actions? This Guy will waste as much of your time as you are willing to give. For your own sake, call a halt and get your head straight. You won’t stop hurting until you draw the line.

DEAR ABBY: Last year I decided to pursue a career as a foreign diplomat. My wife and I weighed the pros and cons and concluded that the opportunity was worth the separation from family and friends. I’m proud that I’ll be able to provide the kind of life for my family that we have always wanted, and I’m set to begin training soon.

We have begun spreading the news, and most of our relatives and friends share our excitement. My wife’s sister, “Lucinda,” however, is furious. Her objections started with snide little “jabs” but have grown into a full-blown assault. She is accusing me of ruining her life and threatening to cut off all contact unless we reconsider. My wife is distraught from the badgering and I’m afraid their relationship is on the verge of collapse.

Should I bow to Lucinda’s threats or follow our dream and risk being disowned by a member of the family? I’m afraid I have inadvertently ruined my wife’s relationship with her sister. — SECOND THOUGHTS IN MINNESOTA

DEAR SECOND THOUGHTS: Unless you want the remainder of your marriage and your career to be dictated by your wife’s sister, do not back down. Lucinda appears to be an insecure, and possibly troubled, woman who is trying to control you and your wife through emotional blackmail. You have a bright — not to mention fascinating — future ahead of you. So follow your chosen path and do not allow your sister-in-law to continue to interfere. To fold now would only be the beginning of your problems.

Dear Abby is written by Abigail Van Buren, also known as Jeanne Phillips, and was founded by her mother, Pauline Phillips. Write Dear Abby at www.DearAbby.com or P.O. Box 69440, Los Angeles, CA 90069.