DEAR ABBY: Some friends of mine and my husband's invited us over for a sit-down dinner at their home. The friends are acquainted with my husband's parents and extended a written invitation to them as well, which I thought was very nice.

Because the friends live some distance away, we planned to carpool there with my in-laws. When my in-laws arrived at our door, they had my sister-in-law with them. (She's middle-aged and still lives at home.) I was mortified because I knew "Sis" hadn't been invited.

I promptly called the hosts to give them a heads-up and an apology, and offered to bring more food. My mother-in-law overheard me on the phone and took great offense and said they weren't going. She said my husband and I were rude because we treated Sis like a criminal. She asked repeatedly before storming off, "What's one more person gonna hurt?" Who was in the wrong here? -- BAFFLED BY LACK OF ETIQUETTE

DEAR BAFFLED: Your mother-in-law was wrong to bring an uninvited guest with her. Assuming you quietly telephoned to warn the hosts, and did not embarrass your sister-in-law by doing it in front of her, your mother-in-law was wrong again in taking offense because you tried to keep the hosts from being caught flat-footed. It was extremely rude to punish the hosts by leaving them with empty seats at their table at the last minute.

DEAR ABBY: This is in response to "Wounded in Midland, Texas," who was devastated because a friend had told her that her deceased husband had had an affair. Twelve years ago, when I was 23, my husband committed suicide while I was in the room with him. Not only did I have to deal with the pain of losing him, but also the guilt of wondering what I could have done to stop him.

At his funeral, several of our "friends" just had to share stories about his infidelities and drug habits with me. They laughed about them. (This was the first I had heard of them.)

I'll never understand why people do that when you're at one of the lowest points in your life. If they couldn't tell me while he was with me, what was the point of telling me then? Losing someone causes enough pain; at least leave us with what happy memories we have.

I, too, went through years of therapy and am now happily remarried for eight years, but I'll never forget those "friends" at the funeral. Needless to say, I haven't seen or talked to them in 12 years. -- ALSO WOUNDED IN WISCONSIN

DEAR ALSO WOUNDED: I'm pleased that you have managed to get past your tragedy and have gone on to have a successful life. Believe it or not, I have actually heard from some people who feel that the widow should be told so that she won't idealize her deceased spouse and will "get on with her life." I have never subscribed to the "for your own good" school of disclosure. Read on:

DEAR ABBY: In response to the lady from Midland, Texas, whose "friend" divulged that her deceased husband had carried on a verifiable affair, she should ask herself, "Why did she tell me this?" The answer, of course, is she wanted to HURT her!

My sister revealed that my son had told his cousin that he didn't care about coming back home again after receiving his degrees. I cried every night after work for three months, until my husband asked me, "Why did she tell you that?" To hurt me, of course. I promptly quit bawling. -- FEELING FINE, PRAIRIE VILLAGE, KAN.

DEAR FEELING FINE: I applaud your husband for his insight.

What teens need to know about sex, drugs, AIDS, and getting along with peers and parents is in "What Every Teen Should Know." To order, send a business-size, self-addressed envelope, plus check or money order for $3.95 ($4.50 in Canada) to: Dear Abby, Teen Booklet, P.O. Box 447, Mount Morris, IL 61054-0447. (Postage is included.)

DEAR ABBY: Anger -- a normal human emotion when dealt with positively and assertively, not negatively and aggressively -- can advance mankind.

However, many people don't have the skills to positively deal with anger because they've never been taught the skills.

Anger-management skills classes should be part of the curriculum in all our nation's schools and prison systems. This would help eliminate some of the depression, domestic abuse, divorces, alcoholism, drug addiction, crime and murder in our country. I believe the benefits would far outweigh the costs.

For people who recognize their anger-management problems and want to learn the skills to enable them to deal with those problems positively, our society should make it "politically correct" to seek help through counseling. In other words, we should drop the stigma, as we have in the last 10 years or so in regard to alcoholism and drug addiction. -- CARL FOX, HURST, TEXAS

DEAR CARL: Although I'm not sure I agree that the "stigma" in regard to alcoholism and drug addiction has been erased, I do agree that anger-management classes in schools could be helpful in lowering levels of violence. A step in the right direction are the peer mediation programs that are being implemented in many schools, which help to defuse problems before they become serious.

DEAR ABBY: You goofed when you advised "Tony's Mom" to buy earplugs if counseling couldn't keep her husband from yelling at their 10-year-old son. All that yelling will only harden the child, and when he reaches his teens, it could become explosive.

I, too, was a "yeller" and found my teen-ager becoming increasingly angry, hateful and disrespectful. Instead of trying to force him to change, I decided to change myself. I focused daily on adhering to the following goals:

1. I showed my love for my son by touching him gently at least 10 times a day with hugs, pats, or just resting a hand on his shoulder when he talked to me.

2. When I wanted his attention I went to him, touching him gently and speaking very softly, looking him in the eye.

3. I listened attentively to his stories, remarks, comments, etc., without judgment or criticism.

4. I stayed in control of my emotions and stopped yelling, which eliminated the power struggles.

This calmer, nicer approach reduced the arguments and resistance to what I asked. It was amazing how quickly I got my sweet, loving son back. -- WISER IN NORTH TEXAS

DEAR WISER: Your suggestions are certainly worth trying -- and in many cases could go a long way toward establishing a more loving family atmosphere.

However, I recommended family counseling because it can provide insight into how these disruptive patterns began, as well as methods for eliminating them and improving the level of communication between all parties.

DEAR ABBY: I am a 15-year-old boy who likes to read Dear Abby. I would just like to say that not just girls read Dear Abby. Please print my letter because I do not want boys to feel left out! -- PATRICK S., CAMARILLO, CALIF.

DEAR PATRICK: You're right. My readership includes all ages and both sexes.

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 $3.95 ($4.50 in Canada) to: Dear Abby, Anger Booklet, P.O. Box 447, Mount Morris, IL 61054-0447. (Postage is included.)

DEAR ABBY: I was stationed at Al Karj Air Base in Saudi Arabia during the holiday season last year. I would like to say thank you to you and all your readers who participated in Operation Dear Abby and sent mail to service members overseas.

We don't always get the chance to answer all of the cards and letters, but they are dear to us. We are grateful to everyone, from the third-grader who prints better than I do, to the 9-year-old whose brother beats up on him (he wins sometimes, though), to the veterans who remember what it was like to be far from loved ones during the holidays.

Abby, please print the military addresses again this year. Our military personnel need those morale-boosters. -- ROGER SURRATT, WHEATLAND, CALIF.

DEAR ROGER: I'm delighted to oblige, and thank you for providing me this opportunity to announce to readers that it's time to launch Operation Dear Abby XV.

My thanks to each and every one of you who has worked to make Operation Dear Abby so successful every year. Your outpouring of cards and letters lifts the spirits of our servicemen and women who are far from home and family, to remind them they are in our hearts.

Many schools and clubs make this a group project, and in years past have sent cookies and packages to the troops. This year, however, in order to ensure that the mail is received within the required time frame and that it falls within the Department of Defense security guidelines, mail will be limited to ONLY first-class letters and cards, 13 ounces or less.

Operation Dear Abby has been assigned four addresses for use during the 1999 holiday season. Specific units and countries are not being targeted, only major U.S. military Aerial Mail Terminals and Fleet Mail Centers overseas. Once mail is received, these mail hubs will distribute it on a fair-share basis to all branches of the armed forces. This means a letter addressed to a "soldier" may be distributed to an airman, sailor or Marine, allowing for wider distribution. This should also prevent the transportation system or specific units from being inundated.

To send mail to a specific area, address it to the closest geographic hub.

FOR EUROPE AND SOUTHWEST ASIA:

Any Service Member

OPERATION DEAR ABBY

APO AE 09135

FOR THE MEDITERRANEAN BASIN:

Any Service Member

OPERATION DEAR ABBY

FPO AE 09646

FOR THE FAR EAST:

Any Service Member

OPERATION DEAR ABBY

APO AP 96285

FOR THE PACIFIC BASIN:

Any Service Member

OPERATION DEAR ABBY

FPO AP 96385

The U.S. Postal Service will begin accepting this mail on Nov. 15, 1999. After Jan. 15, 2000, mail will no longer be accepted for these addresses.

P.S. Readers, if you have difficulty at your local post office, ask the clerk to check recent postal bulletins. OPERATION DEAR ABBY addresses are not always entered into postal computers, and clerks may not be aware that they are valid.

To order "How to Write Letters for All Occasions," send a business-sized, 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, Ill. 61054-0447. (Postage is included.)