DEAR ABBY: My 13-year-old daughter, "Dena," is in the same grade as her friend "Amanda." Amanda has a sister, "Barb," who turned 15 last month. Amanda told my Dena that Barb's 16-year-old boyfriend has been sneaking in Barb's bedroom window several nights a week for a while now, after their mother and stepfather have gone to bed. Amanda also confided that Barb told her that she and the boyfriend have had sex a couple of times, including before Barb turned 15.

I am not close to the mother and stepfather, although I do run into them at school functions. I wouldn't begin to know how to approach the parents and tell them what I know. Should I be concerned with what's happening in other people's homes after they've gone to bed? Or should I keep this to myself and let them find out the hard way down the road? -- ANOTHER MOTHER IN OKLAHOMA

DEAR MOTHER: Do unto others as you would have them do unto you. Call that girl's mother and tell her what you know and how you learned it. If what your daughter's friend confided is true, they need bars on the windows and a chastity belt for Barb (and some serious counseling).

DEAR ABBY: I work in the mailroom of a large company. Every day we deliver the mail that is sent to the people who work here. On some occasions, I deliver mail to people who have private offices. Sometimes, these people are having a meeting in their office and do not shut the door. When this happens, should I just give them their mail, or wait until they are finished talking to that person? I'm asking because sometimes I get dirty looks from those people while I'm giving them their mail -- like, "How dare you come into my office while someone is in here!"

Abby, I don't talk to them and I try to stay out of their way, because I know that someone walking in can be distracting. What is the correct mailroom etiquette? -- CONFUSED DELIVERER

DEAR CONFUSED: The universal signal for "Do Not Disturb" is a closed door. If the door is open, then you should be free to enter. However, since you are being given dirty looks for making deliveries while there is a conversation in progress, the next time the person is alone, ask what he or she would prefer under those circumstances. Another suggestion would be to stand quietly in the doorway for a few seconds and wait for the person to acknowledge you and motion you in.

DEAR ABBY: I have been married to "Kurt" for 13 years. It's a second marriage for both of us. Kurt consistently fails to introduce me at social functions and leaves me to fend for myself. At the last party we attended, he left me to talk to the most attractive blond woman there -- someone we had both just met. At the end of the evening he hugged her and told her to call when she's back in town.

I told Kurt his behavior hurt my feelings, and if he respected me he wouldn't act this way. He says I'm out of line. What do you think? -- SOCIALLY ABANDONED IN BEND, ORE.

DEAR SOCIALLY ABANDONED: Your husband appears to suffer from social amnesia -- he "forgets" he's married when the two of you go out. You are not out of line; he is. If he had any consideration for your feelings, he would at least check back every 15 or 20 minutes to see if you're still breathing. Shame on him.

Good advice for everyone -- teens to seniors -- is in "The Anger in All of Us and How to Deal With It." To order, send a business-size, self-addressed envelope, plus check or money order for $5 (U.S. funds only) to: Dear Abby, Anger Booklet, P.O. Box 447, Mount Morris, IL 61054-0447. (Postage is included.)

DEAR ABBY: I'm a 25-year-old recent college graduate who just started a new job. I love it here because I'm doing something I care about and earn decent money. I like all of my co-workers with the exception of one. This person, "Jim," interrupts my work a lot, says things like "Hey, beautiful!" and calls me things like "baby girl." The other day he said, "It's too hot outside." I replied cheerfully, "Sorry, I had nothing to do with it," and he said in a creepy manner, "You have a lot to do with it."

This is bothersome because I think Jim is a nice person, but he makes me uncomfortable. He has worked here a lot longer than I have. I don't want to say anything to the boss because I'm the new girl. I have been here only a few weeks, and I don't want to make trouble.

At the same time, I'm tired of Jim walking into my office, sitting down, talking for long periods and making off-color remarks. If I close my door, I'll appear anti-social, but I'm tired of being badgered because he's bored or because I'm the only young female in the office. I don't want to get anyone in trouble -- I just want it to stop. What should I do? -- TRAPPED IN NORTH CAROLINA

DEAR TRAPPED: You are entitled to be comfortable in the workplace and free from unwanted conduct. State and federal laws guarantee you the right to be free of unwelcome talk based on gender. Ideally, you should tell this man that he is making you uncomfortable. However, if you cannot bring yourself to do it, I urge you to document what is going on and bring your concerns to the attention of your boss or the person who handles human resources at your company.

DEAR ABBY: I am a 26-year-old female in the Navy. I have been divorced for two years and have two beautiful little boys.

Last February, I met a man and I have fallen head over heels. He's great with my boys and wonderful to me. He has expressed that although he loves my kids, he also wants children of his own. My problem: I had a tubal ligation after my youngest was born, and now I regret it. I think this is the only thing that is preventing us from going to the next level. What should I do? -- HELPLESS IN WASHINGTON

DEAR HELPLESS: Call your ob-gyn and ask if the tubal ligation can be reversed. It is sometimes possible to reverse the procedure. (The same is true of a vasectomy.) If it is not possible, consult an infertility specialist. These days, there is more than one way to skin a cat or become a mother.

DEAR ABBY: Our son is married to a sweet girl whom we love. My only problem with her is that she has no pictures of us in her house. She has wedding pictures on display, and some of her family and friends -- but none of my husband and me.

They have a new baby, and I go there and take care of him one day a week. She has a baby book with photos, and there are no pictures of us in there, either.

We haven't said anything to her or our son, but each time we go there it bugs me. I came home upset the other day, and my husband said to let it go. I'm afraid if I speak up, my son will say I'm overreacting. What should I do? -- SAD IN AKRON

DEAR SAD: Have a nice photograph taken of yourself and your husband, autograph and frame it, and give it to your son and daughter-in-law for Christmas.

For an excellent guide to becoming a better conversationalist and a more attractive person, order "How to Be Popular." Send a business-size, self-addressed envelope, plus check or money order for $5 (U.S. funds only) to: Dear Abby Popularity Booklet, P.O. Box 447, Mount Morris, IL 61054-0447. (Postage is included.)

DEAR ABBY: I star in adult films. I am not ashamed of what I do, but sometimes other people's reaction to my profession can be severe.

I am trying to get my 4-year-old daughter, "Ashley," accepted into an exclusive religious day care. The problem is that on the application I am to state my profession, as well as her father's. My husband, "Rex," is also in the adult film industry.

Rex thinks we should just lie. I want my daughter to be accepted, but I know Ashley will be turned down if they find out we lied on the application. What do you think? -- "TEMPEST" IN L.A.

DEAR TEMPEST: You don't have to lie. State that you are in the movie business. Just don't mention that the movies you're in are "blue," and cross your fingers that you don't run into any fans.

DEAR ABBY: Our 31-year-old son is being married soon in the Midwest. We would like to know what our financial responsibilities are -- if any -- regarding the costs of the wedding, in light of the following:

1. Our travel expenses will be about $1,500, plus an additional $500 for hotel and food.

2. Although 100 guests are invited, we do not know them, as they are all friends and relatives of the bride and her parents.

3. We are giving our son and his bride a gift of $1,000.

4. We have no say in the planning of the wedding.

We want to do what is right, but we don't want to pay unless tradition or etiquette demands it. Please advise. -- PUZZLED PARENTS IN OREGON

DEAR PUZZLED PARENTS: Although it is not obligatory, it is customary for the groom's parents to host the rehearsal dinner the night before the wedding. The guests should include the bridal party, the bride's parents, the fiances and/or live-in companions of the bridesmaids and ushers, and the clergy who will officiate. The bride's mother can help you select an appropriate restaurant.

DEAR ABBY: Two former teachers made an incredible impact on my life. Both encouraged me to stretch far beyond what I thought possible for myself. They pushed and nudged me, praising my efforts in pursuing my dreams. I promised myself I'd contact them "one day" to let them know how much they influenced my life.

A few months ago, I finally contacted my old high school to see if I could locate them. To my dismay, I learned that one had been killed in a car accident the year before, and the other had gone to the hospital last spring and passed away without ever going home.

I feel terrible. I never had the chance to tell two wonderful people how much they mattered. Please urge your readers to stop right now and make that call. We may never have the chance again. -- TOO LATE IN CLEVELAND

DEAR TOO LATE: That's a lesson I'm sorry you learned the hard way. Kind thoughts are meant to be shared; they do no one any good if you keep them to yourself. To paraphrase a poem I heard years ago: "If you're ever going to love me, love me now. Don't wait until I'm gone and have it chiseled on my headstone; let me hear it while I'm living, so I can enjoy it."

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 $5 (U.S. funds) to: Dear Abby -- Keepers Booklet, P.O. Box 447, Mount Morris, IL 61054-0447. (Postage is included in the price.)