DEAR MISS MANNERS: I am wondering if I committed a faux pas over breakfast while staying at my sister’s house. When my cousins and I gathered in the dining room, we were told of the various breakfast offerings on hand: muffins, rolls, biscuits, eggs, waffles and so on. My sister also told us that there were various cereals available, in addition to the other things mentioned, and to help ourselves to whatever we liked.

As is my habit, I took a small bowl of cereal with milk to my place at the table, along with a muffin. As I did so, I received an extremely long, icy stare from one of my cousins, who was having only a muffin and a glass of juice.

Is it improper for one guest to have something more than what other guests are having? Should I have limited myself to what the cousins were having? And while I’m at it: Wasn’t it impolite for my cousin to stare at me disapprovingly? It’s not as though I gorged myself at the expense of others, and our host did tell us to help ourselves!

GENTLE READER: As long as you were not swiping the last muffin out from under your cousin’s lips or hoarding all of the breakfast foods, you did nothing wrong. Invitations may be taken at face value, as long as a modicum of fairness, decency and regard for others accompanies their acceptance.

However, Miss Manners does not guarantee that your cousin is not holding a lifelong childhood grievance about unfair practices between you when you were 8. But she does not have time for such passive aggressiveness -- and nor should you.

DEAR MISS MANNERS: I have a relative whom I talk with a couple of times a week by phone. During our calls, the relative’s girlfriend can be heard talking in the background as if she is on our phone call herself. It makes it difficult to speak with my relative.

I have said a few times, “I cannot hear you because of the background noise.” I have asked her to call me back when she can have a quiet conversation, but each time she returns the call, the girlfriend starts up again.

I really do want to continue phone calls with my relative. Do you have a suggestion for handling this situation?

GENTLE READER: Get to know the girlfriend.

It seems to Miss Manners that that is probably what she is seeking -- and that calling her “background noise” is not helping the situation.

If, after you have taken the time to know her, she is still chiming in on telephone conversations, you may then say, “Oh is that Clarabelle? Please put her on. I have been meaning to ask her about her recipe for succotash.” Clarabelle may find herself suddenly too busy for an actual conversation, but at least you will have made the point that one-on-one is preferred to a chaotic free-for-all.

(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: On a small-boat river cruise my husband and I booked in Europe, the vast majority of our fellow travelers were enjoying the opportunity to explore the local cultures, foods and customs.

But unfortunately, one of them spent most of the time setting passive-aggressive traps for the crew of the boat. This person would place an order for an exotic favorite drink from back home, then berate the bartender when the presentation did not match all the details from their hometown bar. When the bartender offered (three times) to alter the drink to meet expectations, the response was, “You obviously don’t know what you’re doing; just take it away.” Similar demeaning comments were directed to the chef, the cabin attendant and the local guides.

The senior crew members did their best to step in to take the worst of the abuse. Fellow travelers were embarrassed by the behavior and wanted to mitigate the situation. At various times, we pulled the crew members aside to offer our apologies. We wanted to confront the aggressive passenger, but no one could devise a polite way to intervene. If we encounter a similar situation in the future, what would Miss Manners suggest?

GENTLE READER: No society can function without an agreed-upon code of etiquette, but the problems of not having one become apparent more quickly among those thrown together -- and kept -- in close proximity for an extended period of time.

Who, then, enforces the rules? Both the crew and the other passengers acted correctly, but it was not enough. Such efforts having failed, it was time for the captain (or some other officer in a recognized position of authority) to speak with the unruly passenger.

Any sensible captain would be happier ordering passengers into lifeboats, and may feel hesitant to intervene, remembering that the charges are also paying clients. But such is the burden of command. Judgment must be exercised in determining when such an extreme step becomes necessary, but Miss Manners trusts the captain to act before a full-fledged mutiny occurs.

DEAR MISS MANNERS: What are your thoughts on expectant mothers and fathers throwing themselves baby showers?

My friend has apparently decided that the two showers already given by friends and family in her honor did not result in a sufficient haul of gifts. She and her husband are now throwing themselves a diaper shower, even going so far as to assign each invitee a particular brand (the most expensive, of course) and size of diapers to donate to the cause.

This couple is not in need of financial assistance. Is this type of excessive gift-grabbing the new normal? I’m not sure how to respond to the invitation.

GENTLE READER: It may be the new normal, which does not make it acceptable to either Miss Manners or those who are repeatedly expected to cough up time and money. The proper response is to find that you have a prior engagement on that particular day.

(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: I hosted a dinner at my home for some close friends, and one texted the day before to let me know that she would not be able to attend; however, her husband would still be able to make it. They had taken it upon themselves to invite a friend of theirs named Bert in her place.

I had met Bert on prior occasions and have always been appalled at his rude manners. Anything from lecturing me about my “obesity” to arrogantly correcting anyone within earshot is the norm for him.

My friends seem oblivious to his behavior, even though it happens right in front of them. He has chased away many guests at their home, due to his sharp words. While I can simply remove myself from his presence at their gatherings (or more often, I don’t attend many of their gatherings anymore), I would not have the same option at my own table. I certainly would not want to subject my guests to his belligerent attitude.

The fact is, he is not welcome in my home. I was in a very difficult situation, since my friends had already issued the invitation. I couldn’t use the excuse that I wouldn’t have room at the table, as the wife would be absent and Bert would be occupying her spot.

I told her that I didn’t mean to be offensive, however, I needed to be able to trust that Bert would refrain from being rude to me and to my guests. She was taken aback, as she insists that he is “a sweet guy.”

I happen to know that several others have disagreed with her on this point over the years. In the end, the husband and Bert did not show up, and my friend is quite offended. I’m sure that I could have handled it better, but I’m at a loss as to what could have been said. Whenever anyone has tried to discuss the topic with her, she completely denies it and is very insulted. How could I have politely conveyed that it is not appropriate to invite someone else to my home, especially someone that I don’t even like?

GENTLE READER: The specific problem you mentioned is simpler to answer than the general problem you propose. Rather than exact a pledge for Bert’s behavior, you could have -- if you feel as strongly about Bert as you indicate -- apologized, but explained that Bert is not among the guests you invite to your home.

This creates a problem for the friend who violated this rule by inviting him, but not for you. And while the answer may upset her, Miss Manners notes that your less direct approach had the same effect. Less extreme situations require less direct answers, with a less guaranteed result: “You know how Bert is an acquired taste, and while we should definitely get together, my other guests are very sensitive and will not get his sense of humor.”

(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.)