DEAR ABBY: Here's one for the books on parental stupidity. When my daughter, "Marissa," began to reach her teen years, her father -- in an attempt to be funny -- advised her that she could keep from becoming pregnant by putting an aspirin between her knees and keeping it there.

My stupidity was assuming that sex education and pregnancy prevention were taught in her school. I never broached the subject with her.

Marissa became pregnant at 15. The young man she was seeing told her she couldn't get pregnant in a swimming pool because the chlorine would kill the sperm. Have you heard that before? Needless to say, the inevitable result was a baby.

I love my grandson dearly. God did not make a mistake even though we adults were all dummies in the advice department. Please tell parents, children and adults to educate themselves and learn all the facts and fictions about teen pregnancy and prevention. -- STUPID MOM WITH NO EXCUSE IN NEW JERSEY

DEAR MOM: Your letter underscores the importance of parents taking the initiative and discussing sex and values with their children before hormones kick in and peers fill their heads with misinformation about birth control.

Some popular misconceptions include the idea that jumping up and down after sex prevents pregnancy, that douching with Coca-Cola is an effective contraceptive, that you can't get pregnant during your menstrual cycle, that "withdrawal" prevents pregnancy, and that you won't get pregnant if it's your first time or if your breasts aren't developed.

It is vitally important that parents talk to their children about sex because many schools offer only abstinence-based sex education -- which has not slowed the spread of STDs. According to the April 2005 issue of Journal of Adolescent Health, teens who pledge to remain virgins until marriage are more likely to take chances with other kinds of sex that increase the risk of STDs.

For parents who have difficulty discussing sex and values, I offer my booklet, "What Every Teen Should Know," that explains not only sex and contraception, but also the important topics of sexually transmitted diseases and date rape. My booklet has been distributed in doctors' offices and used to promote discussion by educators and religious leaders. It can be ordered by sending a business-size, self-addressed envelope, plus check or money order for $6 (U.S. funds) to Dear Abby, Teen Booklet, P.O. Box 447, Mount Morris, IL 61054-0447. Shipping and handling are included in the price.

DEAR ABBY: I was married last June. I wrote my thank-you notes for our wedding gifts a week after returning from our honeymoon. I thought they had been mailed.

It is now 11 months later, and I found the cards in the trunk of my husband's car. What do I do? -- CATHI IN STOCKTON, CALIF.

DEAR CATHI: You should mail them now. A late thank-you is far better than none at all.

DEAR ABBY: I'm writing regarding "Puzzled but Still Going Strong" (May 19), who lost weight but is being undermined by her husband. It is possible that the man is co-dependent.

Simply stated, his identity or comfort level is dependent on the wife remaining overweight. When she loses weight, the husband loses a piece of his identity or becomes afraid he will lose his now-slimmer wife to another man. In co-dependency, the co-dependent partner will do everything he/she can do to undermine improvements in the other partner.

Counseling is critical for this couple -- or "Puzzled" alone, if her husband won't go -- to address this issue. Otherwise, he will wear down her resolve. -- DEBBIE IN PENNSYLVANIA

DEAR DEBBIE: Thank you for your comments. My readers were quick to weigh in on this topic, which affects many families across the country, given the pervasive increase in obesity reported by health-care professionals. Read on:

DEAR ABBY: Five years ago I had gastric bypass surgery, and since then I have lost 120 pounds. Numerous pre-op tests were performed before my surgery, but one of the most important "tests" was that my husband was interviewed by the surgeon prior to the procedure.

He was asked if he had any concerns about how the surgery would change our lives and if he would have any problems with me losing the weight and being the same person with a different body. He was informed that my eating habits would drastically change and that, if the surgery was to work, my world could no longer be centered around food.

Apparently the medical profession knows the importance of spousal support for weight loss. Perhaps "Puzzled" should make an appointment with her family doctor so he (or she) can explain to her husband how much healthier she is since losing the weight. -- HAPPY IN FLORENCE, KY.

DEAR ABBY: While it may be insecurity on the husband's part, it is important to note that all the examples "Puzzled" gave of the man's behavior are methods of control, as well as providing a very poor role model for the children. Not only is he attempting to sabotage her efforts, but he is teaching their kids that he is less dedicated to the cause than she is. It could also be something more serious. Belittling and demeaning someone is abusive, even though it doesn't leave visible bruises.

Abby, your advice about professional counseling was right on, and I hope for her sake and that of her children, she gets it sooner rather than waiting to see if he "eases up." I know from experience that it is much harder to undo negative role modeling than it is to set a healthy and positive example. -- MOM WHO'S BEEN THERE, DONE THAT AND GOT THE T-SHIRT TO PROVE IT

DEAR ABBY: Several years ago I lost 40 pounds and have kept it off with diet and exercise. My wife's response was to gain 40 pounds. She said she was so angry with me for getting in shape that she decided to get even. She eats everything she wants, never exercises, and now weighs more than 200. Despite many weight-related health problems, she has no intention of changing her habits. My advice to "Puzzled": Resist your spouse's attempts to derail your fitness with all your might. -- RESIGNED IN ALABAMA

DEAR ABBY: "Puzzled" may have become a "diet bore." All too often, dieters shut out everything but themselves and their diet. You CAN have a healthy life that includes your spouse, family, and the things you used to do together. It just requires some balance. I prefer to call it a lifestyle and not a diet. -- WISE WEIGHT WATCHER

Abby shares more than 100 of her favorite recipes in two booklets: "Abby's Favorite Recipes" and "More Favorite Recipes by Dear Abby." Send a business-size, self-addressed envelope, plus check or money order for $12 (U.S. funds)

to: Dear Abby -- Cookbooklet Set, P.O. Box 447, Mount Morris, IL 61054-0447. (Postage is included in price.)

DEAR ABBY: My friend "Nora" was very shaken by something that happened to her recently. While her six grandchildren were visiting, the oldest boy (age 13) shouted, "Let's take her down!" and all six of the children attacked her, knocking her to the ground, then groping and hitting her.

Nora is 73 and only 5 foot 2. Her oldest grandchild is 5 foot 7 and weighs 140 pounds. All of the grandchildren are large for their ages. The youngest, who is 7, weighs well over 70 pounds.

My question is, what can elderly people do to protect themselves? Nora felt helpless. She took the beating because she was afraid if she fought back, she'd be turned in for child abuse. I told her I'd have whacked that 13-year-old monster so hard he'd think twice about ever pulling a stunt like that again.

Now she's afraid of her grandkids because, even though their parents eventually pulled them off her, they did nothing to punish the children for their aggressive behavior. Is there anything older people can do to defend themselves against delinquents? -- SHOCKED IN TOPEKA

DEAR SHOCKED: Are you talking about delinquent children or delinquent parents? Nora's grandchildren were obviously never taught by their parents the importance of behaving respectfully around adults, particularly elderly adults who can be fragile. They could have caused their grandmother serious harm. That the behavior went unpunished is extremely disturbing because if parents don't bother to teach their children right from wrong, their misbehavior could escalate.

While the incident you described might be considered "fun and games" when it occurs between children, when it happens with an adult it becomes assault and battery. In Nora's case, it could be considered elder abuse.

There are two ways to protect oneself from "delinquents" of any age who act like this. The first is to avoid people who do not understand boundaries because their lack of judgment could sooner or later cause great bodily harm. The second is to notify the police and seek immediate medical attention.

DEAR ABBY: How do you tell people you just don't like them and don't want to be friends anymore? My husband, daughter and I are "friends" with a family we became acquainted with when our daughter was in first grade. That was three years ago.

This family is annoying and loud, and we can't seem to distance ourselves from them. They constantly call for playdates and dinner dates. The kids get along well, but my husband and I do not like this couple and prefer not to spend our social time with them. How do we distance ourselves without offending them? -- STUCK IN SAN ANTONIO

DEAR STUCK: Since when did an invitation to get together become a command performance? You are under no obligation to accept every invitation that is offered to you. The kindest way to extricate yourselves would be to simply not be available every time they want to get together. Cultivate other friendships for yourselves and your daughter.

P.S. I am not advising you to necessarily end the friendship between the children. But when you arrange time for them to get together, make it a time when they are dropped off at each other's homes.

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 $6 (U.S. funds) to: Dear Abby, Anger Booklet, P.O. Box 447, Mount Morris, IL 61054-0447. (Postage is included.)