DEAR HARRIETTE: My 20-year-old son has a 19-year-old girlfriend who is well-endowed and rarely wears a bra. She also wears low-cut clothing and often looks like she's about to fall out. The dress she was wearing the other night was so small on her that she could barely zip it up all the way, and a nipple was close to making an appearance. When she walked in the door, she looked at me, shrugged her shoulders and said, "I know this is a low-cut dress," as if she knew what my expectations are, but came looking like that anyway.

My son's girlfriend is going on vacation with us in three weeks. I don't want to seem prudish, but I do want to get through to her that this type of dress isn't appropriate for the places we'll be going and the people we'll be seeing. I'll be asking her before we leave if she has bras in her suitcase, and I am ready to leave her behind if she doesn't or make her go out and buy a few.

What else do I do? I don't want to alienate her, but how do I help her to understand that something that is fine when you're out clubbing is not fine when you're trying to make a good impression with your boyfriend's family? -- Appropriate Clothing, Atlanta

DEAR APPROPRIATE CLOTHING: At the very least, you can establish the rules of your home, which should also be the rules of traveling with you. Your situation reminds me of childhood. My father had many rules, including wardrobe guidelines, that everyone had to follow. Once, a boy with cornrows in his hair came to visit my sister. This occurred way before this style was a trend, and more as a way of setting an afro (making it an at-home style, in my father’s eyes). My dad told him to go home and do his hair before coming inside our house. He required all of us to dress up for Sunday dinner, which meant a dress for girls and a shirt, tie and jacket for boys. Strict? Yes. But we had to follow the rules.

Similarly, you can take this young woman aside and share your expectations about personal presentation. Tell her that you think her style of dress is too provocative and is unacceptable in your home. Be sure to tell your son how you feel and what you intend to say so that it comes as no surprise. You absolutely can put your foot down on this. Hopefully your son will recognize that your family values do matter.

DEAR HARRIETTE: Over the years, I have had a contentious relationship with my sister. Whenever we talk on the phone, I expect to have some friction or for her to belittle me in some way. So I always have my guard up when we begin to talk.

For the past few months, ever since the family got together for our mom’s birthday, she has been nice. I’m not quite sure how to react to it. There have been no barbs or mean comments. Do you think we have actually turned a corner? Part of me is afraid to relax. I don’t want to get my feelings hurt again. -- Turing Point, Los Angeles

DEAR TURNING POINT: Claim the positive. You are strong enough to let your guard down and see what happens. Assume that your sister sees the value in being kind to you -- finally. If she slips and shows her mean streak from time to time, point it out. Tell her you like the “new” her much better. Ask her to stay nice.

(Harriette Cole is a lifestylist and founder of DREAMLEAPERS, an initiative to help people access and activate their dreams. You can send questions to askharriette@harriettecole.com or c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO 64106.)

DEAR HARRIETTE: I got into a big argument with a woman I hired to help me work on a project; she has been flaky pretty much the whole time. I tried to be calm with her, but her lack of professionalism and overall sloppiness sent me over the edge. We tried to get back on course, but she continues to be late and act lackadaisical about her duties. I have written up a strong reprimand that concludes with firing her. I showed it to a colleague, and he suggested that I sit on it and then try to find less intense language. This is hard for me. I want it to be clear to her that the way that she has worked -- or not -- with me has put me in a horrible position. I don’t want to be nice. What do you think? -- Over the Edge, Boston

DEAR OVER THE EDGE: It’s good that you conferred with your co-worker before sending the message. When you are upset, is it wise to sit on a communication for at least a day to allow you to simmer down and look at the big picture. An incendiary firing will only create an incendiary ending that could have lasting negative reverberations. It is far better to speak and write in measured words as you fire someone. Tell her that the relationship is not working. If you must, list breaches of protocol specific to the project. Do your best not to crush her emotionally. In Michelle Obama’s words, “When they go low, we go high.”

DEAR HARRIETTE: My mom died a few years ago after a prolonged illness. My dad has found a new woman to share his life, and they are now engaged. The problem is my sisters. We are all adults with families of our own. They don’t like his fiancee at all. They are rude to her and behave like spoiled children. She is different from our mother, but our family has always been open-minded and taken pride in our conviction that “normal” is just a setting on the dryer.

She isn’t after Dad’s money, nor is she forcing her way into our lives. She’s also not trying to replace Mom. It appears she genuinely cares for our dad, which I can understand: He’s a good man -- smart, attractive and fun to be with. Dad is happy as a clam. He’s enjoying himself and has lots more life to live. The thing is my sisters’ attitudes are putting a damper on my dad’s happiness. What can I do to help them? I don’t want to be too harsh because I know they are still grieving, but I hate to see them drive a wedge into what remains of our family. -- Happiness for My Dad, Portland, Oregon

DEAR HAPPINESS FOR MY DAD: Call a family meeting, and address your sisters directly. Remind them that your mother is gone. As much as you miss her, you cannot bring her back. Point out that your father deserves to have joy in his life, and he has found it. You do not have to love this woman, but you do have to respect your father’s decision and be gracious. Ask them to imagine how they would feel if their husbands passed and their children were rude or dismissive about whatever happiness they may have discovered after the loss.

(Harriette Cole is a lifestylist and founder of DREAMLEAPERS, an initiative to help people access and activate their dreams. You can send questions to askharriette@harriettecole.com or c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO 64106.)

DEAR HARRIETTE: I’ve been dating an awesome man for about three years. Everything was great while we lived separately for the first two years. We decided to move in together about three months ago, and two weeks after that, his son's mother fell into a coma due to drinking. My boyfriend’s 8-year-old son is now with us full-time and will probably be with us for a long time.

I am now acting as a mom and wife, but without the actual titles. My boyfriend has said he's "just not there yet" when it comes to marriage and that at this point he would be marrying me only to make me happy. I feel stuck now that I am living with him and his child even though he doesn't see us getting married. Meanwhile, I’m a successful professional in my 30s. How can he not want to marry me? What should I do? -- Playing House, Syracuse, New York

DEAR PLAYING HOUSE: This is an unusual circumstance that has shaken your boyfriend, and indeed, all of you, to the core. Still, you two need to take the time to assess what you want in your lives. If you want to be married, you need to lay it out for him clearly so that there is no question about your intentions. If you didn’t do that already, you have some course correction to handle. If you want to be committed to him and are willing to care for his child long-term, tell him. If you are not willing to play mom indefinitely without being his wife, say that. He deserves to know where you stand.

If you believe he will not make any changes, help him to figure out ways to care for his son before you leave. You may have to walk away if your boyfriend can’t take full responsibility for the changes that this tragedy has created.

DEAR HARRIETTE: What's an appropriate way to respond to my pregnant girlfriend who told me the name she's selected for our baby? She asked what I think, and the truth is that I think she's punishing our child for life with such a silly moniker. But she's obviously put a lot of thought into it, and I don't think anything positive will come from me sharing my thoughts. Is it OK to lie so she’s happy, saying, "Nice, how original!"? And on a similar subject, what's a good way to shut down the conversation when friends start gossiping about her choice? -- What's in a Name?, San Francisco

DEAR WHAT’S IN A NAME?: You have every right to participate in naming your child. I believe that names help to pave the way for people. In some traditions, the elders “divine” the name of a child with the intention of guiding the child’s steps. Others incorporate family names to ensure that children know whence they come. Tell your girlfriend your thoughts about her name choice. Suggest you discuss it together, and consider a range of names before agreeing on one. Get things straight with her before you have to deal with friends.

(Harriette Cole is a lifestylist and founder of DREAMLEAPERS, an initiative to help people access and activate their dreams. You can send questions to askharriette@harriettecole.com or c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO 64106.)