DEAR ABBY: My father was born 50 years ago, and only learned the truth about his birth in the last few years.

The woman he always believed was his mother was, in fact, his grandmother. His older "sister" was really his mother. She was 16 when she became pregnant by a young soldier who denied responsibility.

His grandmother, a strong-willed woman, took his mother to another state and pretended she had given birth. She was deeply ashamed of her daughter, and went to great lengths to carry out the plan. She wrote letters home to relatives informing them of her "surprise" pregnancy -- even describing her terrible morning sickness.

Abby, my father has been estranged from both women since learning the truth. My great-grandmother is 88 years old. I pray that our family can be healed before it's too late. Dad is angry, betrayed and bitter. He refuses to discuss the matter, much less forgive. The saddest part is that some family members have told me they knew the truth all along, but kept silent.

His grandmother felt the charade was the only thing she could do under the circumstances. However, this kind of deception reverberates through several generations. -- SECRETS ARE DANGEROUS IN NEW YORK

DEAR SECRETS: I feel sorry for everyone involved in this fiasco. Your grandmother was trying to protect her daughter's reputation, because in 1950 being unmarried and a mother was considered a disgrace to the girl and her family. She was trying to protect your father, too, by bringing him up when her daughter couldn't, and from the knowledge that he was born out of wedlock.

He should have been told the truth more than 30 years ago. But family secrets sometimes have a life of their own, and she probably couldn't find the words by the time he was an adult.

That your father is bitter and hurt because he was lied to about his history is understandable. However, some sessions with his clergyman or a therapist might help him to let go of his anger and forgive the deception -- before it's too late.

DEAR ABBY: Please settle a disagreement between me and my fiance. Several of his co-workers have had weddings recently, with more to come. It is their practice to invite only their co-workers, stressing that no spouses or significant others are invited. This is not true of their other guests, only their co-workers. I have heard they believe the people from work are not as much fun when their spouses or dates are around.

All these weddings have been in halls with light buffets or appetizers and cash bars. They are always held at night with a DJ and dancing. They are not formal.

My fiance's co-workers are almost all female. Therefore, he's the only dancing partner for 10 to 15 women who are without their husbands or boyfriends.

I think this practice is extremely rude. My fiance believes it is their prerogative and the "modern" way of doing things. What do you think? -- STEAMED IN CONNECTICUT

DEAR STEAMED: People usually limit their guest list because of budgetary concerns. Your fiance is correct that it's the host's privilege to issue such an invitation. All the same, to invite only half of a committed couple (a spouse or fiance) to a wedding where there's music and dancing is a breach of etiquette. To quote the lyrics of Irving Berlin, he should be able to "change partners and dance" -- with you if he wishes.

For everything you need to know about wedding planning, order "How to Have a Lovely Wedding." Send a business-size, self-addressed envelope, plus check or money order for $3.95 ($4.50 in Canada) to: Dear Abby, Wedding Booklet, P.O. Box 447, Mount Morris, IL 61054-0447. (Postage is included.)

DEAR ABBY: "A Dad in a Dilemma" wrote that his ex-wife informed him she's moving in with a registered sex offender, and he's concerned about sending his girls to stay overnight with her. Your advice to not let his daughters stay at their mother's house was correct.

I am a police detective in a sex crimes unit. Probably 90 percent of our sexual assault victims are children. Sex offenders, especially those who victimize children, have a very high rate of recidivism. Additionally, many child sex offenders are prohibited from having ANY contact with children under the age of 10 and can be arrested if they do so.

"Dad" can contact his local law enforcement agency or the man's probation officer to determine whether the man is allowed to have contact with minor children. Even if there is a custody arrangement which states that his ex-wife gets to see their daughters, he should contact the attorney and do everything possible to keep the girls from having any contact with this man. He should not rely on his ex to provide the proper supervision, as she has already shown a severe lack of judgment in exposing her other child to this risk. -- POLICE OFFICER IN COLORADO

DEAR POLICE OFFICER: Thanks for adding your expert opinion to my original advice. "Dad in a Dilemma's" letter generated a flood of mail from alarmed readers. Read on:

DEAR ABBY: I work with an attorney who handles the legalities when children are removed and detained by child protective services. We have a number of cases where children were removed from one parent because of socialization with sex offenders.

"Dad" should research this person's criminal background. If he can't get the full history, he needs to get the local law enforcement or child protective services agency involved. -- A WORD TO THE WISE, CRESCENT CITY, CALIF.

DEAR WISE: A helpful suggestion. Read on:

DEAR ABBY: You were right telling "Dad" not to let his daughters visit his ex-wife. No sex offender should have such easy access. Even though the mother might be present in the house, sex offenders need only a moment to satisfy their twisted urges.

"Dad" would be wise to notify the court that issued the custody award for the daughters of the changed circumstances and to seek an immediate modification of the visitation. (This is in case the ex-wife wants to exercise her visitation rights despite the obvious risks.) A modification of the decree would prevent such a problem.

If "Dad" can't afford a lawyer to get the change made, most state bar associations have a list of attorneys who will work "pro bono" (for free), and many attorneys, once aware of the circumstances, will help because they are parents also. -- AN ATTORNEY WHO CARES

DEAR ATTORNEY: I am sure your advice about "pro bono" legal services will be of interest to many people. Thank you for it. Read on:

DEAR ABBY: As a survivor of child sexual abuse, I know what can be lost if "Dad's" daughters end up in the clutches of this registered sex offender who was convicted of aggravated assault on a 10-year-old.

The fact is, the ex-wife's new boyfriend is a danger to "Dad's" girls. He should insist that his ex sign a legally binding document that visitations NEVER occur in the company of her boyfriend. Period. If she refuses, he should take it to court. "Dad's" daughters must be protected from their mother's bad choices. -- STILL SURVIVING IN L.A.

DEAR SURVIVING: How true.

To order "How to Write Letters for All Occasions," send a business-size, self-addressed envelope, plus check or money order for $3.95 ($4.50 in Canada) to: Dear Abby, Letter Booklet, P.O. Box 447, Mount Morris, IL 61054-0447. (Postage is included.)

DEAR ABBY: Although I read your column daily, I have never had a reason to write until now. I read the obituaries and have noticed that lately there are female pallbearers listed. Is this proper, or should it be a man's role? I always thought that men were supposed to do it. I'm sure other people wonder about this, too. -- VICKI IN JOPLIN, MO.

DEAR VICKI: In the days when coffins were actually carried, it required strong men to lift them. However, today the coffin is placed on a church "truck," and it's perfectly acceptable for women to be pallbearers.

In early America, it was the women who cared for the dead. It was they who bathed and shrouded the body for burial. In a sense, women are now taking their rightful place again by acting as pallbearers. It is much better when family members of both sexes physically participate in funerals. Doing so can be therapeutic. Twenty years ago morticians were mostly men. Today, 40 percent of graduating morticians are women, according to the Funeral Consumers Alliance. Instead of being ghoulish, the business is becoming "girlish."

DEAR ABBY: My husband of almost 25 years presented me with a beautiful diamond heart necklace for Valentine's Day. Now I am trying to decide if I should keep it.

Several years ago, he had a "female friend." One of the things that hurt most was finding out that he had bought her expensive jewelry. Among the items was a diamond heart pendant.

When I opened the gift, all I could think about was her. Should I explain to him that, although the necklace is very beautiful, it brings back painful memories? Are men really this dense? -- CRYING IN CALIFORNIA

DEAR CRYING: Apparently your man is. Dry your tears and tell him, as tactfully as possible, that while you are grateful for the gift, his selection has painful associations for you. The two of you should return it and select something more appropriate.

DEAR ABBY: I am a professional woman marrying another professional woman. We have lived together for two years and are able to communicate very well. We are growing and changing beautifully as partners.

Because it is not legal in the state where we live, we will be going to Vermont for a private ceremony. My question: How do we approach the wedding reception with those family members who are not "comfortable" with it? We don't want anyone to feel slighted, but at the same time, we don't want to deprive those members of the family who offer support and take joy in our union. Do we invite everyone and just see who shows up? -- NEEDS TO KNOW

DEAR NEEDS TO KNOW: Send invitations to everyone you would like to have at your reception, including those who are not comfortable with your union. If they don't wish to attend, they will decline. You already know some of them will not welcome this marriage, but extending the invitation will show them that you want to encourage close family relationships. And you may be surprised that some of them may put aside their misgivings in the interests of family unity.

Abby shares her favorite recipes in a two-booklet set. To order, send a business-size, self-addressed envelope, plus check or money order for $7.90 per set ($9 per set in Canada) to: Dear Abby Cookbooklet Set, P.O. Box 447, Mount Morris, IL 61054-0447. (Postage is included in the price.)