DEAR MISS MANNERS: I am having trouble with my sister, Caroline, and my fiancee, Emily. Caroline is my twin, and she is married and has a 9-month-old baby girl.

Caroline has done nothing to endear herself to Emily. Emily has tried to be friends, and Caroline rebuffs every attempt. She has declined dinner and party invitations, and has not been any help in the wedding planning at all. We had asked her to be a bridesmaid, which makes Emily think that Caroline should be more helpful and enthusiastic.

Even worse, my Emily wanted the wedding to be adults only, but Caroline simply told her that the baby was part of the family and would be coming. This has upset Emily greatly -- not just the part about bringing the baby, but also the rude way it was done.

Caroline has now responded to a bachelorette party invitation by first saying she would come for one day, and now saying that it is too far to drive. She says she "may" meet them at a winery, but we all know that is a lie.

Emily wants me to say something. I actually understand why Caroline wouldn't want to go to the bachelorette party -- she does not know anyone else there and would be uncomfortable. She also has a baby.

I think Emily may be a little oversensitive about this. Also, I didn't go to my brother-in-law's weekend bachelor party (partly because I didn't know anyone, partly because of work, and partly because I didn't want to make anyone feel like they had to be on their best behavior).

As for the baby at the wedding -- she is my niece, and I don't see what the big deal is in having her. All the baby will do is be a part of the photos and then sit in a high chair at the dinner. Yes, Caroline may leave early with the baby, but it doesn't hurt my feelings at all.

Naturally, Emily thinks I should be supporting her more. Who is right? Who is wrong? Do I have to be in the middle, or should Emily call Caroline and tell her how she feels?

GENTLE READER: You are in the middle, and you will be living there ever after if you don't settle this now.

The worst thing you could do would be to take sides. These are not combatants; they are, or soon will be, your family. The successful diplomat leaves everyone thinking that he sympathizes with her.

Therefore, you do not tell Caroline that she should be participating more in the wedding, that she should understand that her baby is not welcome, or anything of the sort. Rather, you say: "Emily wants so much to be friends with you, which would also mean a lot to me, and she is afraid that she might have inadvertently offended you. I don't think she understands how busy you are with the baby. We wish Zinnia were a bit older so that she could be a flower girl, but of course we want her at the wedding."

And how do you explain this to Emily? You do not tell her that she has to compromise. Rather, you say: "You know I will always be supportive of you, in every way. I'm sorry Caroline is being standoffish and snippy, but I think we can bring her around. It may be that she is just frazzled with the baby, so letting her bring her would help. Besides, Zinnia will be your niece, and I know you feel as I do that family is important. But let's not make an issue about the bachelorette party, because Caroline could throw it in my face that I didn't go to Josh's. If I'd had you to advise me then, I would have behaved better."

(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, Universal Uclick, 1130 Walnut St., Kansas City, MO 64106.)

DEAR MISS MANNERS: When did it become usual to omit the titles Miss, Ms., Mrs. or Mr. in mail addresses? Most of the cards I receive are addressed simply with my first and last name.

This is done not just by young people, but also by older people, even some my age, and I am 85. Is this commonplace among people who are not courtesy-minded, or is it part of the growing lack of class and refinement in our society?

GENTLE READER: It began with a lack of refinement on the part of recipients of letters. This was an unfortunate consequence of the well-intended change allowing married ladies flexibility in styling their formal names.

The trouble started two or three centuries ago, when it became standard to use the husband's full name when addressing the wife, as in Mrs. Clarence Huckleberry. Miss Manners was amazed at how long it took for those ladies to notice the consequences: successive wives of the same person taking the same name, no sensible way to be addressed properly at work, and so on.

Then Ms. came back into use, as it had been for the previous centuries as an abbreviation for "Mistress," the once-respectable honorific that went with first names regardless of marital status. That was an especially timely revival, as more brides were keeping their original names.

But this time, it arrived as an option, offering freedom, at last, from the rigidity of a single system.

And what did everyone do with this newly granted freedom? Ladies who used Ms. for themselves started offending their grandmothers by denying them the formal names they had always used, which was especially hurtful in the case of widows. And they became the targets of those who spurned what they thought of as a newly minted, awkward title.

Accusations were hurled: "They think my husband owns me!" "I'm proud of having my husband's name, and how dare they deny it to me?" All very tedious.

The situation was compounded by the difficulty of remembering everyone's personal choice. Miss Manners still hears from those who are indignant at not being addressed as they wish, and those who are bewildered at being vilified for a simple mistake. We are at the ridiculous state where it is possible to insult people simply by sending them invitations or letters of thanks.

Many victims of this just got fed up and stopped using any courtesy titles. Miss Manners agrees that this is a crude solution to a problem that would not exist if people only gave one another the benefit of the doubt and showed some tolerance and flexibility.

DEAR MISS MANNERS: As a homemaker, I do not have a business card to hand out. Is it proper to ask to exchange phone numbers or emails with strangers and to let them know you would like to become more acquainted?

I am quite friendly and would like to possibly make new friends of people I meet in a store, at a dance, on a trip, etc. Once I asked another woman in a restaurant if she would like some company while dining. We had a pleasant time together.

Is that proper, and could I have asked her for a phone number? My grown children seem to make friends of strangers in situations like these.

GENTLE READER: It's not improper if you don't scare the stranger. There are enough scams around to make people wary of giving out such information.

Miss Manners suggests that you volunteer yours instead. You need only jot down your number or email and say, "I've enjoyed talking to you and would be delighted if you got in touch."

(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, Universal Uclick, 1130 Walnut St., Kansas City, MO 64106.)

DEAR MISS MANNERS: My husband prides himself on having good manners and teaching our children good manners.

The one thing I have a problem with is that I come from a very open and welcoming family. When my nephew asked if he could come visit on Saturday, of course I said, "Sure, it would be great to have you come over."

As he was leaving his house, he phoned to inform me that he was bringing some friends with him. I know this is not the most polite thing to do, especially since they were arriving at dinnertime before heading out to dance at a club.

So at 5:30 p.m., my nephew and five of his friends, all about 19 to 22 years of age, arrived at my house. My mother and sister were over visiting, so we headed out to the store to get wings and pizza, which my mother paid for.

While we were out, I received a text from my husband saying that he was furious that my nephew had invited his friends over. I understand this.

However, when we arrived home, and my nephew showed up with his friends, my husband left the house. My mother and sister asked where he was, and I said he slipped out to the store to pick something up.

When my husband arrived back, he did not come and join us; he sat upstairs with a drink and snacks and ignored everyone, including my mother and sister.

I understand he was not happy with the situation -- but enough to be rude? As well, he is not speaking to me and is still furious with me.

How do I address this? Should I just accept that he is right? I don't think that two wrongs make a right, but maybe I'm wrong here. Should he have been more polite even though he was not happy with the situation?

GENTLE READER: But you said he prides himself on having good manners. So why isn't he ashamed of himself?

Petulance is a violation of etiquette, as are ignoring guests and taking out bad moods on innocent parties.

Yes, Miss Manners is well aware that he will claim that your nephew was rude to bring friends. But guess what? "He started it" is not an acceptable defense for being rude. It is indeed the essence of good manners to behave well when one does not feel like doing so.

DEAR MISS MANNERS: I currently live on a college campus, and therefore I spend almost all my time eating at campus locations. At these locations, they provide, in baskets, paper napkins and disposable forks on each table. I have become known among my friends for a habit in which, when asked to pass "a napkin" or "a fork," I pass the entire basket and let them choose. I was taught that this is only polite, but my friends see it as a curious idiosyncrasy. Who is correct?

GENTLE READER: Not only are you right, but you could get into just as much trouble doing the wrong thing. In a crowd that makes fun of you for a trivial gesture that happens to be correct, Miss Manners doesn't doubt that if you lowered your standards to theirs, one day someone would say, "Eewww -- I can't eat with that fork after you touched it."

(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, Universal Uclick, 1130 Walnut St., Kansas City, MO 64106.)