DEAR MISS MANNERS: My ex-husband and I have been divorced for over 20 years. We see each other at family functions and are very cordial and polite with each other, as is his girlfriend, who also attends these events.

Neither of us has remarried. He has been in a relationship with this female for many years, but they don’t live together.

When our sons had their first babies, my ex wanted the family to refer to his girlfriend as Nonna ("grandmother"). Our sons immediately shut that idea down, stating that their children already have a grandmother, and that they would refer to the girlfriend by her first name. This was out of respect for me, and also to avoid confusing the children.

But recently, while visiting one of my sons, my daughter-in-law and I were having a conversation about my 9-year-old grandson. She was relaying something that my grandson had said about his grandfather’s girlfriend, and referred to her as "Nonna."

Immediately, I asked, “Is he referring to her as Nonna now?” He never had before, nor had anyone else in the family. She replied, “Yes.”

I immediately said that I was not comfortable with that, and that it really bothered me. The girlfriend can be the substitute Nonna after I die (which I’m not planning on doing anytime soon).

Am I wrong in feeling that my grandchildren already have a grandmother, and that the title should not be shared with their grandfather’s girlfriend?

GENTLE READER: How you feel about it is not Miss Manners’ department. Nor is basic biology, though she cannot help noticing that even if you were not divorced, your grandchildren would have had to grapple with the "confusion" of having two grandmothers, assuming their mothers’ mothers were still alive.

Etiquette can comment on some of the terms being used (or misused). Your ex-husband and his girlfriend are outside of normal usage in applying "grandmother" to a nonresident non-relative -- just as you are outside of normal usage in applying "cordial" to a relationship with someone you refer to as “this female.”

Had your ex remarried, his then-wife could have claim to the title of grandmother. But even without that, you have no right to dictate what the grandchildren call anyone other than yourself.

DEAR MISS MANNERS: I am a typical middle child in that I’m always trying to help everyone in the family and keep them happy. I take on most of my parents’ care because my sisters have families at home, and I’m single with grown children. I work 60 hours a week, I’m the safe venting place for my children, and my significant other wants time, too, obviously.

This is too busy on its own, but I also have a serious mental illness (bipolar). I manage it well and am very high-functioning. But how do I tell people they’re overwhelming me when each person’s need is relatively small on its own?

GENTLE READER: Handle the smaller requests by protecting your time, rather than rebuffing them individually. So, for example, you may not wish to answer nonemergency calls or texts after dinner.

Miss Manners realizes this refusal to reply instantly will strike some denizens of the modern world as sacrilegious, but never fear: They will eventually discover the method for themselves and write books about how they were the first to suggest it.

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

DEAR MISS MANNERS: I am a man with curly hair. A year ago, I decided to grow it out. Today I went in for a haircut. I told the barber that I was growing it “classical musician” long, but that I needed the bottom of the back trimmed up. I expected it could use a little bit of shaping up all over, as well.

When he was finished and turned me around so that I could see it, my hair was SHORT. As in, the back was a quarter-inch long. I was stunned.

Without comment, I paid him (including the tip). I am beyond frustrated. Is there anything I could have said or done?

GENTLE READER: After the deed was done, no. But next time -- at a different barber’s -- you might wish to pay more attention while the operation is in progress.

Miss Manners suspects some other distraction was at play -- a phone, perhaps, or the classical music on the salon speakers. The lack of direct access to a mirror does not, by itself, explain why one would not notice all that hair cascading onto the floor.

She does not mean to be unsympathetic, but not everything in life has an undo button.

DEAR MISS MANNERS: I work for a midsized company that has a centralized administrative office, in addition to locations where we do field work. I am part of the administration, and work permanently from my office.

The unwritten policy is that we leave our office doors open, although we are allowed to close them for short periods if we are on the phone or need to work uninterrupted.

There is a conference room located directly beside my office that is utilized multiple times daily. Before and after these meetings, people will congregate in the hallway in front of my office door to talk. Occasionally someone will even lean on my doorjamb with their backside in my office.

The conversations are loud enough to be disruptive, even if I am wearing headphones, and they are also blocking my exit path if I were to leave for any reason. Sometimes these conversations will last in excess of 10 or 15 minutes.

I cannot ask the meeting participants to go somewhere else, because they are project managers, department VPs, clients and the HR department with prospective employees. Would it be rude of me to get up and gently close my door while they are standing there conversing? Or is it better to just grin and bear it?

GENTLE READER: To answer your question, it’s worth examining why you cannot just (politely) ask these people to gather farther away. It should not be because they outrank you, but rather because what they are doing is (or is presumed to be) in furtherance of company business.

For the same reason, not only can you gently close your door so as to be more productive, but Miss Manners would think less of any boss who thought less of you for doing so.

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

DEAR MISS MANNERS: In the era of selfies, I’m as guilty as anyone of holding my phone out and snapping a photo of my spouse and me in front of some interesting feature. Those photos stay on my phone, or maybe on a social media account, but no further.

Conversely, my grandparents, of blessed memory, who never even heard the word "selfie," had 8x10 studio photographs of themselves framed and hanging on the walls in their respective living rooms. I also inherited large-format portrait photos of two pairs of great-grandparents, both of which are in fairly elaborate frames. They now hang in my living room.

Though it was obviously once common, I don’t know anyone who has framed portraits of themselves in their homes now.

An oil portrait of my spouse and me isn’t in our budget, but I have been considering hanging a professionally composed and framed photo of us in our home. Would this come across as narcissistic? Or is it simply a loving continuation of a three-generation tradition?

GENTLE READER: Who, in what you so aptly named the Era of Selfies, will dare to raise the charge of narcissism? And which is more blatant: including yourselves among family in your own living room, or posting it for all the world to see?

Showcasing painted portraits of oneself was considered acceptable because they were presumably valued for their artistic merit, rather than their subjects -- and never mind that the subjects had commissioned them in the first place.

If you want to be above reproach, Miss Manners suggests that you avoid pictures in which you are shaking hands with the president or displaying the biggest fish you ever caught. But frankly, she doubts that there is much danger these days, when modesty is no longer considered a virtue, but rather an unfortunate lack of self-esteem.

DEAR MISS MANNERS: I had dinner party guests arrive 45 minutes early. They weren’t confused about the time, they just came early. What should I have done?

I sat them in the living room, got them each a drink and then abandoned them for 45 minutes while I changed clothes and finished up in the kitchen. They seemed peevish when I finally joined them, but honestly, what should I have done?

GENTLE READER: Seated them in the living room, given them drinks, and then abandoned them while you changed clothes and finished up in the kitchen.

Too bad they didn’t ask Miss Manners what they should have done: not arrived early, apologized if they did, thanked you for the drinks, and assured you that they would be fine sitting in the living room until you were ready.

DEAR MISS MANNERS: I received an invitation to a 60th wedding anniversary party, and it states: “ABSOLUTELY NO GIFTS.”

What can I do for the lovely couple, who have been family friends for many, many years? I really want to give them something!

GENTLE READER: Then give them something priceless: a letter of appreciation about them and the friendship.

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