DEAR HARRIETTE: I'm worried that my son is going to turn out to be a player. He's only 18, but already he has had multiple girlfriends at the same time, broken several hearts and smiled about it. I really don't like this behavior. He is charming, much like his dad used to be, and is turning out to be bad news for girls. As his mother, I don't want to sit around and watch him turn into a regular old lothario. How can I get him to curb his behavior? His dad does nothing but egg him on when he hears about his antics. That's part of the reason why I divorced him. He didn't see the value in a monogamous marriage. I want my son to share my values. Help! -- Playboy's Mom, Los Angeles

DEAR PLAYBOY'S MOM: You can continue to reinforce your values to your son. Talk to him about his behavior and how it affects those around him. Ask him if he really thinks it is OK to hurt women's feelings, to lead them on and to date more than one person at a time. As he answers, talk openly with him about his beliefs and counter with yours. Describe to him how women feel when they believe a boyfriend duped them.

If you are clear that he is going to be a so-called "lothario," suggest that he be honest with his dates and let them know up front that he is not the monogamous type. At least then they will know what they are getting into.

If at all possible, talk to his father about resisting the temptation to encourage his disrespectful behavior.

DEAR HARRIETTE: My best friend broke her arm recently so she can't go to the gym or play or anything. Now that the weather is nice, my friends and I like to go to the park and ride bikes. I feel bad that she can't participate. A group of us are planning to go to the park this weekend, and I don't know if I should even invite my best friend. I don't want her to feel bad when we are playing. But on the other hand, she might enjoy just being with us. What do you think I should do? -- Friend in Need, Brooklyn, N.Y.

DEAR FRIEND IN NEED: Chances are your friend will be very happy to be invited to join the rest of you in the park. You can set up an area for a picnic that can be location central where she can be when you are doing something she cannot do.

As a good friend, you can periodically go and hang out with her. You two can walk around or sit and talk. Your other friends may want to do the same. Being together is what's important. By all means do invite her, and then remember her when you are at the park!

DEAR HARRIETTE: My next-door neighbor has two young children who play the violin. I don't mind listening to them practice during the day if I'm at home -- it's sweet to know that they are learning an instrument. It stops being sweet, though, when the playing extends way into the night. The other day, these two kids were bowing those strings at around 11 p.m. on a Wednesday night. I thought that was way too much.

I don't want to be the nasty neighbor, but I don't think it's unreasonable to expect that loud music -- even when it's live -- should stop before 11. What do you think? And should I say anything about it? -- Sensitive to Sound, Washington, D.C.

DEAR SENSITIVE TO SOUND: You have mentioned only an isolated incident when you heard the children playing very late. Who knows why they were playing at that time? Perhaps they were playing for guests or for some other one-time reason. If late-night playing becomes a habit for them, that's when you can speak to the parents and request that they end their playing a little earlier on weeknights. Otherwise, just take a deep breath and be grateful that the violins are not drums!

DEAR HARRIETTE: My 15-year-old daughter just informed me that she thinks she contracted a sexually transmitted disease. I could not believe my ears. I didn't even know that she was sexually active -- and I wouldn't call myself naive. We have talked about sexual activity, protection, our values -- the whole nine yards -- for years. Anyhow, she learned she might have this from the boy she had sex with who told her he had it. I suppose we should be grateful that he said something, but OMG, what are we going to do? Do we go to her pediatrician about this? I'm embarrassed to tell him, but she doesn't have a gynecologist yet. I am mortified. What should I do? -- Shamed by STD, Syracuse, N.Y.

DEAR SHAMED BY STD: Your job as your daughter's parent is to get her immediate medical care. Ideally, you should go to a pediatrician who knows her health history. If you feel too uncomfortable to do that, you can go to one of those urgent care facilities where your daughter can be tested and she can receive whatever treatment is deemed necessary.

Be sure to tell the doctor that you visit what STD the boy says he has contracted so that they definitely test for that as well as the rest of the STDs, including HIV. Then follow up with your pediatrician at some point to update your daughter's chart. Further, since she is sexually active, it is time to go to a gynecologist. Find one who works with teenagers and who can help you educate your daughter about safer sexual behavior. While you may not want your daughter to continue to be sexually active, you probably cannot control that, so your job now is to guide her to be as responsible as possible. For support in talking to your daughter about sex, visit plannedparenthood.org/parents/talking-kids-about-sex-sexuality-37962.htm.

DEAR HARRIETTE: My cousin and I had been best friends since we were little girls. As we grew, our relationship became closer. She was my college roommate and my maid of honor. We lived close to each other and hung out on a regular basis. Five years ago, when I was 30, I was diagnosed with cancer. I spent two years undergoing chemotherapy and radiation that put me in and out of the hospital for months. During this low point in my life, my cousin disappeared: no calls, no emails, no texts, not even a visit while I was in the hospital -- nothing. I understood she just did not know how to deal with my illness, but her absence was the hardest part of my cancer experience.

I am now cancer-free, and she has had a child and gotten married. I gave my cousin a gift card, but I did not attend her baby shower. I was invited to her wedding, but did not attend. I cannot pretend like nothing happened. My family sees me as the one causing the rift because of my refusal to make nice with her. My sister tells me that my cousin really wants to know how I am. I miss my cousin terribly, but unless I hear a heartfelt apology from her, I do not see how a relationship can be possible. Am I right in thinking this way? -- Cancer-Free, Chicago

DEAR CANCER-FREE: Unfortunately, many people have a hard time dealing with illness -- either of themselves or of people they love. It is not uncommon for loved ones to retreat during these times, which can be extremely painful to those who are ailing. And it can be difficult to forgive.

Oddly, you probably are the only one who can fix this. It is likely that your cousin is so embarrassed or so distracted by her child -- or a combination of both -- that she is paralyzed and unable to act. Reach out to her. Tell her how much she hurt you and that it is hard for you to let go of that pain. Tell her you miss her and want to find a way back to each other. This may open the door to an honest conversation.

DEAR HARRIETTE: My son is 13 years old and in the seventh grade. He is freaking out because his voice is changing. I personally think it is funny to see my son go through puberty. He is concerned because he does not know what kind of voice he will have in the morning. For the past few days, his voice was as deep as Barry White, but there are days when he sounds like Kermit the Frog. How can I calm my son's nerves during this transition period in his life? -- Daddy Dearest, Salt Lake City

DEAR DADDY DEAREST: Navigating puberty can be challenging for the child and the parent, as it is fraught with ups and downs and plenty of changes. For a boy, the growing larynx prompts the changing voice and can cause him to feel extremely self-conscious. The good news that you can share with him is that the cracking, changing voice usually completes its transformation after a period of just a few months. Knowing that this aspect of puberty will end soon may help him to endure it better. For more information on a boy's voice changes, visit kidshealth.org/parent/general/body/changing_voice.html. For general information about puberty, read "It's Perfectly Normal," by Robie H. Harris.