DEAR ABBY: As the mother of a teen-age girl who has chosen to have sex, I urge other parents to look at the reasons their teen is going outside the family for affection and attention. Perhaps instead of feeling devastated by the fact that their daughter is no longer a virgin, parents should explore the other things going on in her life.

The girl should be made aware that because she has said "yes" once doesn't mean she has to say it again and again. There is a growing movement for "secondary virgins."

I urge parents to have meaningful discussions with their SONS about their responsibility in the matter. Teen-age girls should not have to accept the entire responsibility. Not only are 13- and 14-year-old girls having sex, 13- and 14-year-old BOYS are also having sex. They, too, need information and responsible advice. -- DISAPPOINTED BUT SEEKING HELP

DEAR DISAPPOINTED: Your daughter did not become sexually active because she was looking for the kind of affection and attention she could receive from her family. The reasons that teen-age girls start having sex can range from wanting to be popular, to thinking it will "hold" a boyfriend, to loneliness or curiosity.

However, I wholeheartedly agree that because a teen-ager has sex once does not mean that she (or he) must do it again.

DEAR ABBY: I know you have been asked this question hundreds of times, but I need some answers.

I am a 29-year-old woman. I am constantly told that I am good-looking, and I wish I had a dollar for every man who has asked, "How come a pretty girl like you isn't married?"

I am friendly and have no hang-ups that I'm aware of, but I just can't seem to meet the right man. I refuse to go out with married men (some have asked). I would like to date more, but I have no idea how to find single, decent men. Any suggestions? -- CLEMENTINE (NOT MY REAL NAME)

DEAR CLEMENTINE: Your question is one I receive frequently. (Too bad I'm not running a dating service; there are just as many men asking where they can find a decent woman.)

One of the first booklets I published is titled, "How to Be Popular: You're Never Too Young or Too Old." The message is as applicable today as it was 20 years ago. In a nutshell: Decent people are found where decent people gather.

Get out of the house and become involved. Enroll in an adult education class, learn to paint or sew, or take a class in auto mechanics or computer training.

Volunteer your services. There are plenty of underprivileged, disabled, elderly and teen-agers who could use a friend. Get involved with your political party, your church or a professional organization.

Take dancing lessons -- square dancing, line dancing, ballroom or salsa. Take up fishing or hiking, or join a gym or health club.

Do some entertaining and ask your friends to bring a friend. Let your friends and co-workers know you're available. If you have children, join Parents Without Partners.

P.S. You may not meet someone eligible right away, but you will make new friends -- and they may have a friend who's perfect for you.

For an excellent guide to becoming a better conversationalist and a more attractive person, order "How to Be Popular." Send a business-sized, self-addressed envelope, plus check or money order for $3.95 ($4.50 in Canada) to: Dear Abby Popularity Booklet, P.O. Box 447, Mount Morris, Ill. 61054-0447. (Postage is included.)

DEAR ABBY: The problem: I am a single woman who was out on a dinner date. The food server, who appeared to be in her early 20s, asked to take our order. Just as I was about to reply, the server stopped me and asked if I had looked at the senior citizen menu.

I told her that it would not be fair to order from that menu because I have not qualified for that discount yet. You would think that would have ended the subject, but no-o-o-o. She pursued the matter by saying, "You only have to be 55 to qualify for our senior citizen menu."

Granted, I will be 51 on my next birthday. But don't you think a person should be allowed to ask for the discount, not have the server determine eligibility?

After she left, I made a joke about it to my date, but I must admit that I was upset about the young woman's remarks, and I am afraid that my embarrassment was noticed by my date. Please tell food servers that everyone knows about senior citizen discounts without being nudged. Could I have handled this differently? -- GROWING OLD IN FLORIDA (BUT NOT THAT OLD)

DEAR GROWING OLD: You showed remarkable grace under fire in dealing with the server in front of your date. She was insensitive and clearly out of line.

DEAR ABBY: My husband is more than 50 years old and the oldest of four sons. He has always been loving and attentive to his parents, and they have always responded by treating him like yesterday's newspaper.

His parents always remember the birthdays and anniversaries of their other sons, daughters-in-law and grandchildren, yet they never acknowledge my husband's existence.

We know that they remember the others because my husband is always invited to their birthday dinners, and we sit there while the cards, cash and presents are doled out, knowing his turn will never come. My husband was so hurt he finally asked his parents why they show such partiality. They said the other sons "needed" what they were giving them, and my husband didn't. Since when do you not need love and acknowledgement from your parents?

We are comfortable financially because we work hard and sacrifice. If we don't have the money for something, we wait and save for it. I feel we are being punished because we never ask for help. It's a shame that because we don't whine about always being short of money, my husband is completely ignored. Instead of being proud of their son, they dismiss him because they think he has money. Even if he has money, he still has a heart, Abby, and he hurts like anyone else.

Thanks for letting me get this off my chest. -- OUTCAST

DEAR OUTCAST: Your husband may have thoughtless, insensitive parents, but he has been blessed with a wonderfully compassionate wife.

Perhaps your in-laws will recognize themselves in this column and realize that although their eldest son may be doing well on the outside, he is hurting on the inside, and they can help him with a simple gesture of love.

DEAR ABBY: Will you please answer a question about telephone etiquette? If you call family or friends long-distance and their answering machine answers, is it polite to ask them to return your call? -- RICHARD SHOWSTACK, NEWPORT BEACH, CALIF.

DEAR RICHARD: Yes. And if you really want to hear from them, say, "My number is ( ) and please call me COLLECT."

They may not call you collect, but I'll bet they call you.

To receive a collection of Abby's most memorable -- and most frequently requested -- poems and essays, send a business-sized, self-addressed envelope, plus check or money order for $3.95 ($4.50 in Canada) to: Dear Abby's "Keepers," P.O. Box 447, Mount Morris, Ill. 61054-0447. (Postage is included.)

DEAR ABBY: This is in response to the letter signed "Lesson Learned." You told the sister who wrote it that it is normal for survivors of suicide to experience guilt.

Abby, she didn't have time for a cup of tea because she "didn't have money" to go to a cafe! I'll bet the suicidal sister would have been grateful for a friendly cup of tea at her sister's. Her twin nieces would have distracted her from her own problems. The suicidal sister asked for one Saturday night. Again, the sister refused. I'll bet every Saturday night she spends with her husband will be haunted by her sister's request. I should hope she feels guilt -- not for what she did, but for what she didn't do!

Even though I agree that the suicidal sister was responsible for her own life, she obviously felt very estranged from her family. Perhaps an outstretched hand could have made a difference. Her dead sister made no unreasonable demands. The sister who wrote is feeling guilty because she is!

Abby, you were far too easy on this lady. I'll bet you got a lot of flak on this. -- SANDY IN STUYVESANT, N.Y.

DEAR SANDY: "Lesson Learned" was courageous enough to publicly admit her insensitivity and lack of understanding of her sister's needs. She is clearly suffering, and I saw no need to further chastise her for something that cannot be changed.

Yes, I did receive some flak for my answer. However, I also received some mail that was very helpful. Read on:

DEAR ABBY: I saw the letter about the poor young woman who suffered from depression and chronic fatigue syndrome. I feel deeply for the sister who ignored her sister's call for help. When "Lesson Learned" told her sister that the younger woman didn't know what "chronic-living-life-fatigue is," it was clear that she did not understand that chronic fatigue syndrome is a real disease, for which diagnostic criteria were established by the Centers for Disease Control in 1988. The disease is insidious, leaving the patient constantly exhausted, depressed, and burdened with a myriad of problems.

Many medical professionals do not believe that the disease is caused by a virus, an enzyme deficiency, or any of the other scientific reasons that validate this as a physical disease. They believe it to be "mental" or nonexistent. Because of this, a vast majority of those who have it go undiagnosed. Many patients do not receive the proper medical care because of their physician's lack of interest in a disease with no known cause or cure, so it's passed off as hypochrondria or a mental disorder.

Suicide among those afflicted with chronic fatigue and immune dysfunction syndrome (CFIDS) is high. "Lesson Learned" was devastated by the death of her sister, but it is doubtful she could have done anything to prevent it.

Readers who want more information should write to the Arizona CFIDS and Advocacy Institute, 1125 W. Baseline, No. 212, Mesa, Ariz. 85210. -- THOMAS E. SMITH, PH.D., MESA, ARIZ.

DEAR READERS: You can also contact the CFIDS Association of America Inc., P.O. Box 220398, Charlotte, N.C. 28222-0398 (enclose a self-addressed, stamped (55 cents) envelope) or call toll-free: 1-800-442-3437.

For Abby's favorite family recipes, send a long, self-addressed envelope, plus check or money order for $3.95 ($4.50 in Canada) to: Dear Abby, Cookbooklet No. 1, P.O. Box 447, Mount Morris, Ill. 61054-0447. (Postage is included.)