DEAR MISS MANNERS: Could you speak to the etiquette of costume party dress?

I’ve been invited to a party for adults with a “Christmas pajama contest.” It’s a church group of relatively close acquaintances and friends.

I assume that about 75% of the people will come in their pajamas or a “traditional” Christmas pajamas look; however, a few people are not participating (based on online RSVP messages).

What do you think? Is it proper to come in your pajamas -- whatever they might be? Or should the “red onesie with reindeer” be the goal? And in general, are there standards of dress that supersede any costume party dictums?

GENTLE READER: Yes: One must be fully clothed.

As it is a church group, Miss Manners is assuming that this is implicit. But she has been fooled before -- and the precarious closure on the back of that onesie is just asking for trouble.

However, this is also a contest, so it is likely that most attendees will not be wearing what they wore to bed the previous night. That is both a blessing and not.

Festive but sturdy cotton or flannel pajamas seem safe. Just know that you will likely be competing with electrified Christmas wreaths and inexplicably sexy yule logs.

DEAR MISS MANNERS: I work as a nanny and really enjoy the family I work for. I do not own a car and commute almost exclusively with my bicycle, which is therefore very precious to me.

Unfortunately, the other day, Baby’s papa was doing some home projects and left the garage door open, and my lovely bicycle was stolen. Today Mama and Papa gave me a sum of money nearly equivalent to the original cost of my lost property and apologized for their carelessness.

This was very generous and will help me get back on the road soon, but I am wondering what my obligation is in thanking them. I am usually very good about writing formal thank-you notes for gifts, but since this was a reimbursement for an accident and not a gift, one part of me thinks my verbal thanks is enough and we can leave it at that.

On the other hand, I love this job and these people, and not everyone would have been so generous in their apologies (or even apologized at all!). I would, of course, love to show my appreciation. Can you help me out with this one?

GENTLE READER: What a relief. Miss Manners was fully expecting you to tell her that Papa’s reaction was more like, “It’s my garage door and I should be able to open it whenever I like!”

She is pleased to see that all parties are behaving civilly, and that you are only asking how to make the situation even better.

As the transgression was on the part of the family, a profound verbal thank-you is fine, and a written one not strictly necessary. However, an abundance of gratitude, as well as the reinforcement of gracious and proper behavior, is never remiss, and this is an opportunity to tell your employers how much you value them.

(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 host all holiday celebrations. This is because I have the space and the cooking skills, and for the most part, I enjoy spending time with family and friends and preparing a huge, elegant meal for them. With one exception, the crowd seated around the table always seems to enjoy the feast very much.

However, we have one family member, an older woman, who acts like a spoiled toddler at the table: making faces, gagging and spitting out any food that is not to her taste, then loudly announcing the specific reasons she does not care for the food, and what I should have made instead. She has even gone as far as to remove family favorites from the table, throwing plates full of food in the trash, yelling that she is protecting everybody else from being made ill by that horrible slop!

What she does like are instant foods and canned goods that are doctored up with sugar, garlic, prepackaged seasoning mixes and sometimes bacon. I cook from scratch and have a lighter hand with the seasonings. I try to make sure there are things on the table that she will eat, but she is the only one who wants that stuff, which also makes her very angry. Otherwise, I do my best to ignore the insulting and childish behavior.

My immediate family and I have had a terrible year, full of grief, stress, physical pain and illness, with more troubles on the horizon. I am having difficulty dealing with this extended family member’s outspokenness at times that are not so emotionally loaded as holiday celebrations, and have, on a couple occasions, snapped at her. If it were possible to be out of town for the holidays to avoid the unpleasantness, that is exactly what we would do, but we have obligations at home.

How do I keep my temper in check and create some boundaries while still being a good hostess? Do I somehow find the energy to cook her a big, separate meal in an attempt to keep the peace? Do I do it her way to shut her up, and let everybody else complain? Do I suggest that she go to the Asian restaurant down the road, the only business open over the holidays, if she cannot eat what is on my table? Do I confront her about her behavior? If so, how do I do it in a way that does not make others uncomfortable?

I need a plan, or I am afraid I will be unable to keep from sharing a few honest opinions of my own, and things will get ugly!

GENTLE READER: Take the family member aside -- privately and well before the appointed meal -- and ask how you can help. “I do not seem to be able to please you. I know you have your favorite dishes, but the rest of the family does, too. Perhaps you can help me with a few things that everyone will like.”

There are no guarantees in managing someone whose bizarre hostility has gone untreated. But in Miss Manners’ experience, there is nothing quite so disarming to a tantrum-prone individual than to be spoken to calmly and rationally -- and more important, to be taken seriously.

(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 husband and I went to a restaurant with another couple, they ordered an appetizer of Parmesan fries in addition to their entrees. My husband and I just ordered entrees.

The waitress placed the appetizer in the center of the table, and our friends told us to help ourselves. My husband and I only ate about two fries each, since it was not our appetizer.

When the check came, we noticed that the waitress split the price of the appetizer between the two checks. We didn’t say anything and just paid our half without protest. After all, it wasn’t as if paying for half an appetizer was going to set us back.

I honestly don’t think our friends even realized that we were charged for half of their appetizer. While this isn’t something to be petty about, I hope that this is not a common practice, as I really don’t want to pay for other people’s food. Was the restaurant correct for assuming that the cost should be split, and what should we do if it happens again?

GENTLE READER: Given how strong feelings run on the subject of bill splitting, Miss Manners advises waitresses and waiters, since they are barred from hiding under the table, to request specific instructions from the diners. If they do not, you could turn to the other couple and ask, “How would you like to split this?”

DEAR MISS MANNERS: I attended a wedding of a friend who lied to me about having a bridal party.

When she moved to a different state, she started referring to me as her “best friend back home.” Before she left, I threw a going-away party with a guest list she chose. She asked me not to post the pictures on social media because she didn’t want to offend another “friend.” Why didn’t she just include that friend on the party list, I asked? I talked to her about it, and she apologized and “allowed” me to post my pictures, but I felt like the secret friend.

When she told me she wasn’t having a wedding party, it just gave me a bad feeling. I had a huge medical bill right before the wedding and decided I wouldn’t go. She wanted me there, so she paid for my flight.

The “non”-wedding party members were color-coordinated, did all the bridal duties, sat in the front row AND treated me like trash. One of them slammed the door on me and another snapped at me for coming to check on my friend in the bridal suite. It’s like they saw me as the reason that they didn’t get official titles. Despite her gesture to fly me in, I felt horrible and went home with hurt feelings.

I was treated badly and lied to, but I feel ridiculous bringing it up because she paid for my flight. I wish I’d never gone. Would you keep a friend like this?

GENTLE READER: No.

(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.)