DEAR ABBY: My youngest sister started dating a man and they quickly moved in together. Six months into their relationship she got pregnant and they got engaged. Their wedding is planned for this summer.

Recently she discovered he has been video-chatting with someone he met online. He admitted to flirting, apologized and promised that was the end of it. I have a strong suspicion that there have been other "situations" my sister is unaware of.

Should I express my concerns to her and suggest postponing the wedding? Or should I keep my gut feelings to myself? I'm afraid she will get married and then find out what's really going on. -- BIG SISTER IN MASSACHUSETTS

DEAR BIG SISTER: Be honest with your sister. Although I suspect that your gut feelings are accurate, whether she will believe it is debatable, but at least she will have been warned. If she does decide to stay with him, refrain from any "I told you so's." Recognize that whether she marries her fiance or not, she will forever be linked with him because of the baby.

DEAR ABBY: After my mom passed away, my dad lived alone for three years until his death. During those three years, Mom's family not once made contact with him or me. Dad lived in a very small town. When he would see Mom's sister and her husband out and about in restaurants and stores, they would ignore him.

After Dad's death, my aunt contacted me asking if she could have a rocking chair that belonged to my mother. I agreed they could have it. To my shock, when my uncle arrived to pick up the chair, he began asking me about my dad's belongings. He wanted to look through Dad's tools and such. After making no attempt to contact Dad while he was alive, now that he's gone, my uncle had the nerve to ask to look through Dad's things?! I politely shut him down.

Since then, my aunt has been bad-mouthing me all over town, telling everyone "I dropped them" and "don't want anything to do with them." I suppose that's true under the circumstances, but what should I say to set the record straight without appearing as the bad guy? -- "ORPHAN" IN THE SOUTH

DEAR ORPHAN: Please accept my sympathy for the loss of your parents, and the uncomfortable situation in which you now find yourself. Memorize the first paragraph of your letter to me and recite it verbatim when the subject of your relationship with your aunt and uncle comes up. Because it's a small town, the message will spread quickly, and you won't have to repeat it often.

DEAR ABBY: My husband and I want to go to Europe this summer, but we don't want to take his mother along. We have taken her on two holidays over the last two years and didn't enjoy either one for various reasons. She now expects to go with us on our international vacations, and we don't know how to tell her we prefer to go alone. Please help. -- HOLIDAY FOR TWO

DEAR HOLIDAY: What your husband should say to his mother is, "Mom, my wife and I will be going to __________ for a few weeks in early August. We need an 'adventure' alone together, so we will not be asking you to join us." Period!

DEAR ABBY: Our 22-year-old son stays with us. He has a part-time job and goes to school part-time. He is somewhat secretive. We don't know his friends or where he goes.

One day he brought a male friend over and they hung out in our guesthouse, drinking and playing video games. This went on for several hours and then the blinds closed. My husband wasn't comfortable with that, so he knocked on the door and went in to talk to them. He asked the friend if he had a girlfriend, and the friend said no -- that he's bisexual. Our son then announced that he is also bisexual.

We have only met one girl that he dated and the male friend who was over. The friend did say he isn't interested in our son, that they are strictly friends. I don't think my husband should have quizzed our son in front of his friend.

Our son has a chip on his shoulder and an "I don't care attitude" about many things. He blames a lot of things on his ADHD. He acts like he can't multitask or concentrate on what he's supposed to do. He tries, but if he forgets to do something, he gets an attitude from time to time. I don't know what to think. -- FRUSTRATED IN WASHINGTON

DEAR FRUSTRATED: I can't help but wonder if your husband would have been as curious (and intrusive) if your son had been entertaining a woman in the guesthouse.

Your son has been honest with you about his sexual orientation. He's an adult and should be entitled to privacy regardless of the gender of his companion. He has also been honest about his limitations because of his attention deficit problem.

Unless he is breaking some rule that you and your husband have set in your home, what you should think is that your son is working, taking classes and trying his best to become independent. Perhaps if your husband is less heavy-handed with his questions, your son's attitude may improve.

DEAR ABBY: I have been in a relationship with someone for 11 months. He has full custody of an 8-year-old son from a previous relationship. The mother hasn't been in the child's life for two years. His son knows I am his father's girlfriend and has seen us be affectionate with each other. He has also heard us say "I love you."

Lately, the boy has been saying "I love you" to me, and I am torn about how to respond. We have a good relationship, and I do care for him and his well-being, but I don't know how to respond when he says this. Do I say "I love you" back because I care for him, or should I not respond? I don't know if he's just mimicking what he sees or hears, but I also don't want to teach him that he shouldn't be open about his feelings. -- CAUGHT OFF-GUARD

DEAR CAUGHT: All children want to feel loved. Because you care about the boy, give him a hug and say you love him, too, and always will.

I do have one caveat, however. If your relationship with his father doesn't work out, it is very important that you and the child's dad talk to him and tell him that the breakup has nothing to do with him, that it is not his fault, and he (the boy) will always have a special place in your heart.

DEAR ABBY: I'm close to 70 and have three grown children. I've been a widow for 15 years. My oldest son, age 45, has pretty much cut himself off from our fairly close family. His reason: Two years ago, after I had surgery for lung cancer, he claims I told him I wished I had never had children. This couldn't be further from the truth. All three of mine were planned.

My other children decided the hospital was overmedicating me and that most of what I was babbling was nonsense. I only remember bits and pieces and have no idea whether my recollections are accurate.

I have no problem dealing with my son's attitude; I'm a realist. The problem is the way it's affecting my 90-year-old mother, who lives with me. She feels he has cut her out of his life, too, because of me, and it appears she's right.

How can we convince him he's ripping his grandmother's heart out when he won't talk to either of us? She doesn't deserve such treatment, and he has no right to hurt her this way. -- BEWILDERED IN FLORIDA

DEAR BEWILDERED: If this is the only reason for the estrangement from your son -- which I doubt -- have his siblings talk to him and point out that: (1) You were so drugged up after your surgery you were not in your right mind, therefore you shouldn't be punished or held responsible for any gibberish that came out of your mouth during that period, and (2) it is wrong to punish Granny in such a heartless fashion for something that has nothing to do with her. Perhaps they will be able to get through to him where you cannot.

DEAR ABBY: My husband is a successful man. He is charming in public, but at heart he's a very private person. I was successful in my field, and I'm more outgoing.

He is proud to show me off at parties because people find me interesting and witty, but without fail, at the end of the night he will tell me that somewhere during the evening I "crossed the line." Perhaps I spent too much time talking with another man, or said something he found inappropriate. If I look the wrong way, he accuses me of flirting with someone. Invariably I get a lecture on the way home or the next morning.

I told him this morning that I hate to go out with other people now because of it. He took great offense at that and said, "You are not the victim here. You are the perpetrator."

Sometimes I do say things that come out wrong, but I don't mean them. It would kill me to know that I hurt someone with my words. I am not interested in any other man. I love my husband. What can I do? -- LIFE OF THE PARTY IN VIRGINIA

DEAR LIFE: Not knowing either of you, I cannot determine if your husband is extremely controlling, jealous and insecure, or whether you are doing something out of line. You and your husband could benefit from discussing this with a licensed marriage and family therapist. If he refuses to go -- and he may -- you should go without him.

If your behavior at these gatherings was really unacceptable or an embarrassment, he would not want to "show you off at parties." You shouldn't have to worry that you'll be lectured the next day for just being yourself. Something is definitely wrong here, and I don't think it's with you.