DEAR MISS MANNERS: My son told me last night of a situation where he was severely scolded by his live-in girlfriend. She was fixing dinner, and he went to the pantry to get a fruit bar because he had not eaten since that morning.

She claims that his getting a fruit bar while she was cooking dinner was incredibly rude. She not only scolded him, but wouldn’t eat dinner with him.

I contend that it was not rude unless he made a comment to the effect that his snack tasted better than what she was cooking. Do you agree? I’m guessing she has some other issues she has to deal with, and part of it may be related to their relationship. But since I told him it wasn’t rude, I was curious as to your thoughts.

GENTLE READER: Even though his mouth was full, did he forget to say “Mmmm, smells delicious. Anything I can do to help?”

While it is understandable to want to defend your son for seemingly innocent acts, Miss Manners feels compelled to remind you of what it seems you are already aware: One never knows what is truly happening inside another’s relationship. Questions that come to mind include: Does his girlfriend always do the cooking and he never offers to help? Does he frequently eat right before a meal she has prepared, and then profess not to be hungry?

Not making a direct comment about the comparative taste of the snack to the dinner did not really solve the fact that he was eating it in the presence of a much more labor-intensive meal. Next time, by asking if he can help, he could accomplish three things: Get on her good side, avoid a fight, and weigh the dinner’s timing against the relative needs of his stomach.

DEAR MISS MANNERS: I have a friend who sends me nice T-shirts for my birthday, Christmas, etc. They are the wrong size. What should I do?

GENTLE READER: Exchange them for the right one.

DEAR MISS MANNERS: I have decided to treat myself to an occasional manicure and pedicure. I am having no luck in finding a salon where the persons doing my nails do not chat away in a foreign language with fellow employees while working on my nails.

The foreign language aspect is rude in itself. Also, I want the full attention of the person cutting, clipping, sanding and polishing my nails. Any advice?

GENTLE READER: Rethink pampering yourself with a transaction that involves people outside your limited circle.

While Miss Manners has sympathy for wanting service industry workers -- especially ones wielding sharp objects -- to pay attention, demanding that they cease all conversation is unreasonable. This might be why you are having trouble finding establishments that will oblige.

Rather than being annoyed, try pleasantly asking the nail technicians to translate so that you may contribute to the conversation -- and even learn something about their culture. Miss Manners has a feeling that this will produce the desired silence much more effectively than admonishment.

(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: Occasionally I come across a customer service policy that is designed to serve the company better, as opposed to the customer. In those cases, I realize the representative is simply relaying the message and most likely had nothing to do with putting the policy in place. Yet I can’t help but show my displeasure to them, as they are acting as the face of the company in that moment.

Do you have a polite way to address this in the future so that I don’t feel I’m flogging the messenger?

GENTLE READER: We expect companies to operate within both social norms and the law; we do not necessarily expect them to be altruistic or work against their own self-interest.

Miss Manners therefore expresses neither cynicism nor disparagement when she expects all company policies to serve the interests of the company: Even a lenient return policy presumably does so by building customer loyalty.

A good company policy serves both company and customer. What you are describing is a bad company policy, which is one that appears to take advantage of the customer. In these days of instant online reviews and customer boycotts, companies promulgate such policies at their peril. The less-understood cost is the wear and tear on their own staff, who are forced to represent the policy and deal with the understandable wrath of you, the customer.

How do you object to the policy without killing the messenger? With a polite but firm demeanor, and a willingness to follow the process through the chain of command -- asking for a manager when a representative is not empowered to solve the problem -- rather than degenerating into a yelling madman.

DEAR MISS MANNERS: My mother, who doesn’t drive anymore, was invited to a wedding about four hours away from the city where we live. I offered to drive her there and said we could spend the night in a hotel before driving back.

Somehow, the groom’s family (the mother of the groom was my mom’s friend) learned that I was in town and insisted I attend the wedding as well.

Beside the fact that I was looking forward to a relaxing few hours sitting by the hotel pool and reading, the wedding was an expensive, formal affair at a very posh country club. I was not prepared to attend a wedding, nor did I want to, not knowing anyone but my mother.

I politely declined. My mother said it was rude of me to refuse the last-minute invitation and that I insulted her friend. I said if the bride had wanted a plus-one for my mother, she would have indicated so on the invitation. Should I have given in and gone?

GENTLE READER: There are hosts who can give “command performances,” but most such hosts command armies. Even they cannot expect 100 percent acceptance of their invitations, although the rate does go up when those armies are used to round up stragglers.

Extending an invitation to you was intended as a kindness on the part of your mother’s friend, but there is no requirement that you accept. You might, however, be more vague about your reason for declining and merely cite a prior, nonspecific commitment.

(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: If you have a robot vacuum cleaner that runs through your house regularly, and it begins its scheduled run while you have casual company over, is it impolite to let it continue, or should the job be canceled? Does it matter if it is currently running in another room, where you can hear it but it is not underfoot?

GENTLE READER: Intelligent appliances are unavoidable, as are, perhaps, the crude attempts to anthropomorphize them by making them surly. It is only a matter of time before your vacuum cleaner orders you out of the way with a sarcastic quip.

Before that happens, Miss Manners wishes to remind everyone that your electronic devices are not your children. Etiquette highlights the distinction by reversing the now-ignored dictum about children: Appliances may be heard, but should not be seen. The robot vacuum cleaner can therefore be left to its own devices if it can be trusted not to make an appearance in the living room. Miss Manners says this in anticipation of the inevitable invention of the washing machine that wanders the house, absent-mindedly looking for discarded socks.

The rule must, however, be adapted to preserve homeowner and guest comfort: for example, turning off the dishwasher that drowns out dinner conversation, but leaving on the space heater that, the boiler having failed, is staving off frostbite.

DEAR MISS MANNERS: Do you have an opinion on acceptable etiquette for those attending musical performances in a casual outdoor setting? I experience frequent frustration, because when I attend a concert, I go to listen and watch the performers. It seems rude to engage in conversation while they are performing. However, the majority of the attendees don’t really seem to care at all about the music, and talk through the entire evening.

I live in a small town, and it is difficult NOT to encounter someone I know at these events, who then talks to me throughout the entire evening, in spite of my subtle signals that I am really trying to get into the music.

I don’t want to be rude or hurt someone’s feelings. I almost feel that the only solution is to arrive later in the performance, when the crowd is larger, so that I can hide in back. But it seems unfair that I have to miss part of the performance because of these people who don’t CARE about the performance. Any suggestions on comments that I could make that could gently give them the hint? Or is it hopeless?

GENTLE READER: Singlehandedly correcting the manners of an entire audience is hopeless, but avoiding conversation yourself is not.

Most people will become discouraged after a few distracted, monosyllabic responses. If not, Miss Manners recommends acknowledging -- sympathetically -- your friends’ desire to have a conversation, then stating that as you particularly wanted to hear this piece, you are going to find a spot closer to the stage. The advantage of a small town is that after you have done this, word will get around that you are finicky about people talking during the concert.

(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.)