DEAR ABBY: I'm writing to warn as many other young women as I can about the dangers of unprotected sex. I thought I had met the man of my dreams. I knew from the beginning he had a girlfriend in his hometown, but he assured me he was breaking it off, so I didn't think twice about starting a relationship.

Well, she moved here and found out about us. He swore to me that there was no one else besides her and me. We have now discovered a third girl -- his roommate -- with whom he was involved.

Abby, he used no protection with any of us. He swore to us all that he always used it and was regularly tested for STDs. Another lie.

Now his former girlfriend thinks she may have picked up an STD from him, and we all have to be tested to ensure we don't have one.

I now know you can't trust anything you're being told unless there's proof. Go with the guy to get tested and demand to be there for the results. If you suspect (or know) he's seeing someone else, always use protection and insist he be tested regularly.

All three of us could have saved our hearts, our bodies and a lot of turmoil if we hadn't been so trusting. This has left a lasting impression, and now we wonder whether we will be able to trust another man again. -- AWAITING THE RESULTS

DEAR AWAITING: Your "boyfriend" was dishonest and irresponsible. You can't be blamed for feeling bitter. Now might be a good time to re-evaluate whether premarital sex is worth the headache and the heartache.

That said, I can't help but wonder how you intended to avoid infection if you and the man of your dreams were having unprotected sex.

Please take this sad experience as a wake-up call, and schedule an appointment with your doctor to discuss all of the consequences that may result from unprotected sex in the 21st century. There are many -- and an inability to trust is among the least of them. If a man doesn't protect his partner, then it's up to her to protect herself -- both from pregnancy and from sexually transmitted diseases, which are rampant.

DEAR ABBY: I recently bought a new cellphone and was assigned a number by the company that sold it to me. I have been receiving calls and messages for the person who had the number before it was given to me. While the number of the person calling or texting comes up, I do not know the numbers of all my friends and associates, so I have been accepting the calls or texts.

At first, I would let the caller or texter know that the person he/she was trying to reach no longer had this number. However, it takes up my expensive minutes to make those replies. Am I under any obligation to contact these folks, or can I just ignore their contacts? -- POLITE IN PENNSYLVANIA

DEAR POLITE: No rule of etiquette "compels" you to respond to these callers and texters, so consider yourself off the hook.

DEAR ABBY: My husband, "Rory," and I both come from close families. Whenever something is wrong, troublesome, etc., in either of our families, we have meetings where the entire immediate family comes together to discuss the issue.

The problem is, I am not invited to his! It's not like I'm a recent addition to this family. Rory and I dated for 15 years before getting married. My family started inviting him to our meetings after we had dated for a year, including discussions about my dad losing his job, my brother's stint in rehab and more.

Rory's family has had lots of similar meetings, but I am excluded because I am not a blood relative. Even when my husband lost his job, I was not invited to attend. I was left sitting out in the hallway with the children and the boyfriend of one of his other siblings.

I am Rory's wife. Shouldn't I be allowed in on the family discussions now that we're married, especially ones that center on my husband? Am I overreacting because I'm so angry about this? How can I overcome this exclusion from his family? -- WANTS TO JOIN IN

DEAR WANTS TO JOIN IN: You are not overreacting. If you haven't done so already, discuss this with your husband. He is the one who needs to make his family understand you are now a full-fledged member of the clan. If their line of thinking is followed to its logical conclusion, then no man or woman who marries in is fully accepted. "What God has joined together, let no man put asunder," the saying goes. The tradition in Rory's family creates division, and it isn't healthy.

DEAR ABBY: I have a suggestion for your readers. When you attend a funeral or a wake, or meet a friend or relative who has been recently widowed, don't say, "If there is anything I can do, just ask." Call the person in the near future and invite him or her to dinner with you. It doesn't have to be a steak dinner or anything fancy. A home-cooked pot roast would be wonderful.

Of all my friends, only one has done this several times. The phone rings and he'll say, "We're having spaghetti tonight. Would you like to come over? We'll throw in another meatball." I get so tired of going out alone to eat, or settling for a sandwich. -- GRATEFUL WIDOWER IN ILLINOIS

DEAR GRATEFUL: When a death happens, sometimes people are well-intentioned, but they feel awkward and don't know what to do. Thank you for writing and giving me the opportunity to remind them that it isn't the food as much as it is the fellowship that matters at a time like this.

DEAR ABBY: The subject is email, which is how so many of us communicate nowadays. When one gets an email from a friend or relative, it seems to me only common courtesy in most cases to acknowledge it with a response, if only to say thanks. The reply need not be immediate, but there should be one, I think. Many people just don't reply. What do you think? -- TOM IN PALO ALTO

DEAR TOM: I think some people may be too busy to respond, particularly if the communication doesn't seem important or contain a question.

DEAR ABBY: I'm 38, married for 16 years and the mother of two small children. I was recently diagnosed with ovarian cancer and had a hysterectomy to remove it.

My husband has cheated more than once in the past, and since my recovery I have realized I never forgave him for it. I kept quiet and pretended I didn't know. Now I am bitter, angry and hurt. He goes out and stays out constantly. He does help with the kids, but I know I don't belong here. I know what I want, and it's not this life with him anymore.

I know I can leave at any time, but I feel my children deserve to be raised with both parents in the home since neither of us had that when we were growing up. (My father died. His parents divorced when he was a toddler.) His family has been my family since the beginning of our relationship.

I want my children to grow up thinking marriage is forever and growing old with your partner is great. I want them to have what I did not. If we are civilized and "pretend to be in love," would my children be OK? I'm willing to stay in this marriage until they are old enough and on their own before I walk away.

Will they understand that I sacrificed my happiness for them to live with both parents? I want to be in love and happy, but would rather raise my babies with their father than someone else. Your advice is greatly appreciated. -- WILLING IN CALIFORNIA

DEAR WILLING: OK. First, let's talk about your diagnosis and the treatment you had. Being diagnosed with a life-threatening illness can cause anyone to rethink how one has been living one's life. It can cause all sorts of repressed emotions to boil to the surface, causing anger, bitterness and hurt. Before making any life-changing decisions, please talk with your doctor, a marriage counselor and your husband about those feelings.

If you think that staying in an unhappy marriage with a man who goes out and stays out constantly while pretending to be in love would be healthy for your children, I'd be less than honest if I didn't warn you that you would be doing them a disservice. Even if you could pull it off and the kids didn't sense the tension between you and your husband, how do you think they'll feel when they are older and realize what they were led to believe was a happy marriage was a lie?

Because you feel so strongly about raising them with your husband, my advice is to make every effort to clear the air and work out your marital problems with him. That said: It takes two to tango. If he is unwilling to cooperate, all of you might be happier if you separated and agreed to an amicable divorce and shared custody. I'm not saying it would be easy, but it can be done if both parties are willing.

DEAR ABBY: I recently received an invitation to a small wedding that specified the attire to be "dressy casual." I'm thinking of wearing a pair of nice black slacks, a white sweater and a black leather jacket.

Is it appropriate to wear black at a wedding ceremony? And who is the dress code guru who decides these matters? -- DAN ON THE WEST COAST

DEAR DAN: My "dress code guru" for weddings is Emily Post. According to Emily, "dressy casual attire" for men is a seasonal sport coat or blazer and slacks; a dress shirt, casual button-down shirt, open-collar or polo shirt; optional tie and loafers or loafer-style shoes with socks. The rule about not wearing black to a wedding was discarded years ago, and it applied to women -- not men.