DEAR HARRIETTE: I am planning a trip sailing around the Caribbean with five other couples. My children could not go on this trip, so most of the couples understood and are excited that we’re having an adults-only trip. The wife of one of my friends has been emailing me to see if her college-aged son can come on the trip. She argues that he’s not a child and needs something to do because he’ll have a break from school. Honestly, I don’t like the kid in the first place, but I especially don’t want this delinquent ruining the adults-only theme. I have been repeating that this is an adults-only trip while the mother reiterates that her son is an adult. She’s not getting the hint. How do I tell her that her son is not welcome on this trip? – Grown- Ups Only, Newark, New Jersey

DEAR GROWN-UPS ONLY: Start with compassion. If your children were available to go, you would be speaking very differently about this cruise. The fact that you don’t want this woman’s son to participate should not negate the sensitivity that the moment calls for. Her son is available to attend; otherwise, he will be alone.

Knowing this, you can still tell her that her son is not welcome, that the invited group represents the adult peers and no children, regardless of their age. You can acknowledge, too, that you understand that she may not be able to attend if she feels her son will want or need to be with her.

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DEAR HARRIETTE: My mother likes my sister and me to write thank-you notes for practically everything. I understand that these notes are seen as polite, but I think she’s just trying to impress her new boyfriend by having us be proper. I’ve had to write a thank-you note thanking her boyfriend and his family for coming to dinner at our house! I feel that is excessive, but I admit I don’t know how far the rules regarding thank-you notes extend. Do you write a thank-you note only after a gift has been given to you? This is what I originally thought, but after writing thank-you notes for practically everything, I realize I may be wrong. – So Very Thankful, Providence, Rhode Island

DEAR SO VERY THANKFUL: Your mother certainly does tend toward the extreme when it comes to the thank-you note. Historically, when someone came to your home for dinner, it was considered good manners for the guest to write what was called a “bread-and-butter note” the next day to say thank you for the hospitality. It is not expected for the host to send a note, although it is friendly to do so.

In your mother’s defense, expressing gratitude is always a good idea. Given what you think is a hidden agenda, you may want to ask her to lighten up. Tell her that you would like to get to know her boyfriend in an organic way, rather than what feels like trying to impress him.

— Lifestylist and author Harriette Cole is president and creative director of Harriette Cole Media. You can send questions to [email protected] or c/o Universal Uclick, 1130 Walnut St., Kansas City, MO 64106.