DEAR MISS MANNERS: Tell me, Miss Manners: What do you think of dinner guests who tell you they are on a special diet?

I have invited two people to dinner who have told me they are on a weight-loss keto diet. It's pretty restrictive. They are not diabetics and do not have other health concerns.

I will absolutely accommodate their wishes. But is it polite for them to tell me what I can/can't serve? To my eyes, they aren't overweight.

I have been on diets myself, but when invited to someone's home for dinner, I just shelved the diet and went back on it the next day. I don't want to dictate to my hosts.

GENTLE READER: People looking to lose weight should be grateful for a meal in which they can eat some, but not all, of the dishes. And probably, Miss Manners would think, not to have you speculate about whether or not they need to diet.

DEAR MISS MANNERS: We've been friends with a couple for over 20 years. Our son grew up with theirs -- elementary through high school, after-school sports, etc. Their son is getting married out of town -- it's drivable for us, but would mean a flight and hotel for our son and his wife. Our friends just informed us that while we are invited, our son and his wife are not, "due to cost."

Our son will be hurt knowing that we, who are capable of giving a generous gift, are invited, but he and his wife, who are scraping by (he is in school and she is teaching), are not. They would have spent their "gifting" money on expenses for attending the wedding -- had they been invited.

Are we out of line to think that this is just bonkers? Surely the groom would much rather have his buddy (my son) at the wedding than us. We thought that this was weird. Do we ask his parents to exclude us from the festivities and invite our son and his wife instead?

GENTLE READER: As a society, we have a disturbing inclination to use money as punctuation in social situations: "So-and-so was rude to me -- and it's worse because I paid a lot of money for the gift."

Miss Manners finds this disheartening. But if we are going to talk about money, let us at least be clear. You say that the host excluded your son "due to cost." This is a rude, clumsy -- and all-too-common -- way of explaining why someone was not invited. You believe the motive was even grubbier: that potential guests were evaluated based on their ability to pay (in the form of wedding presents).

Whether or not you are correct is irrelevant to etiquette -- though Miss Manners might wonder why you consider people you think so little of to be friends.

Nevertheless, it is clearly impolite to negotiate someone else's guest list.

DEAR MISS MANNERS: What should I do when an elderly relative says she wants to get me a birthday present and, when I thank her for her generosity, follows that up by instructing me to order myself something online and then tell her how much it cost? (This relative is not homebound and does know how to use the internet.)

GENTLE READER: Apologize for not having gotten to it yet, each time you are reminded.

(Please send your questions to Miss Manners at her website, www.missmanners.com; to her email, dearmissmanners@gmail.com; or through postal mail to Miss Manners, Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO 64106.)

DEAR MISS MANNERS: When my very best friend of nearly 30 years visited my new home, she brought her daughter. To say the least, they were terrible houseguests.

I share a communal property, including a swimming pool. A few highlights from the two-day visit: The daughter helped herself to all 12 towels at the pool (leaving none for other guests); she ruined carpets by not drying off before going inside; she ate so much there was not enough food for the other residents/guests at dinner; and she was caught snooping in everyone's homes -- drawers and kitchens, among other places.

The entire situation left me quite embarrassed. Even my neighbors/family noticed this terrible behavior. I had planned extensively for the visit; however, without supervision and correction from the mother, this child was out of control.

I hate to lose my relationship with my friend, but I don't care to have the child visit again until the behavior is corrected.

Obviously, this is a VERY sensitive topic -- which, in the past, has resulted in the end of relationships for me. Any suggestions on how to gently approach this? Or even how to decline any future visits?

GENTLE READER: Not all dogs are house-trained and not all friends merit invitations to stay the night. If you cannot entirely suspend stay-over privileges until the daughter has outgrown her current behavior, or has been traumatized by less-gentle hosts, perhaps you can time them to minimize the impact on your fellow residents: winter days when the pool is not open, and evenings when there are fewer residents around.

In saying this, Miss Manners trusts that reasonable efforts to make your guests welcome were already in place. Grabbing all the towels is serious, but a rug that cannot withstand damp feet might be put away for the duration of the visit.

DEAR MISS MANNERS: My husband and I have been married for 40 years. He recently received a generous gift from a relative on his side. He's not great at writing thank-you notes, so I whipped into action and drafted a wonderful, thoughtful note.

I wrote this thank-you in the plural ("we thank you"). My husband wants it to be in the singular, and says if we sign it "with love from us," I'm accounted for.

I maintain that it's mixing pronouns if the whole note is from him, but we both sign it. I know the important thing is that a thank-you is sent, but I'd like for the giver to know that it's from me, too.

GENTLE READER: Until your final admission, Miss Manners was prepared to applaud you for the perhaps-not-entirely-selfless-but-nevertheless-virtuous act of making your spouse appear more polite than he is.

She admits to not understanding why it is important that the giver see your hands pulling the strings. But she agrees that changing pronouns mid-epistle is apt to be confusing, even if it is a violation of grammar, not etiquette.

(Please send your questions to Miss Manners at her website, www.missmanners.com; to her email, dearmissmanners@gmail.com; or through postal mail to Miss Manners, Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO 64106.)

DEAR MISS MANNERS: Is there a charming, polite turn of phrase that I can use when my dinner seating plans are attacked?

I very much look forward to having dinner parties again. I like seating couples apart, so that we might all visit with more people than we see daily, but this has gone over like a lead balloon. It seems like a foreign custom here in America (and I am actually a foreigner).

At my wedding, I caved and seated couples together, but I did separate (adult!) cousins from their parents, and still got complaints. The children and teenagers seated together did not seem to cause as much ire, but some of them didn't know how to behave, which is a different letter.

While here, I have never seen members of the same household seated apart at other people's houses. Of course I never say anything, but as much as I love my husband, I do wish I could catch up with Cousin Autumn about Baby April and talk pleasantly with my husband about new things afterward, instead of listening to another story from our shared life over dinner. He would like the same!

As a bonus, is there a polite way to separate at least us at a family dinner if there haven't yet been seats assigned?

GENTLE READER: The coyness with which couples declare that they can't bear to be parted for the length of a dinner does make for dull parties and missed opportunities.

But Miss Manners suspects that some people are merely shy about where to sit. That is why it is the job of the host to do a seating plan and shepherd people to their assigned places.

However, she cautions you that weddings often serve as reunions for relatives, so seating plans should allow for flexibility.

DEAR MISS MANNERS: Five guests and the host at a dinner party all drank red wine. When all glasses were empty, the host opened a new bottle of wine, refilled her glass and those of two other guests, and set the bottle down between her and the two guests with refilled glasses.

No request was made to the other three guests as to whether they wanted more wine. No one present has a problem with alcohol. Is this normal behavior, and how should people respond?

GENTLE READER: They could respond with, "Please pass the wine." Presuming that they want some.

The response Miss Manners dislikes is your assumption that the host intended to slight some of her guests and hog all the wine for her end of the table. She might better have asked around, but in very informal meals, wine bottles are set on the table and guests are expected to pass them as requested.

(Please send your questions to Miss Manners at her website, www.missmanners.com; to her email, dearmissmanners@gmail.com; or through postal mail to Miss Manners, Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO 64106.)