DEAR MISS MANNERS: Circumstances have placed me in social circles with a couple I have known many years. The wife was my true love from high school. She chose another to wed, and I have always held my tongue and in no way have interfered, or revealed the private hurt the loss of her affection once caused me.

We sometimes meet at group dinners and parties. Whenever I am alone with her husband, my old rival, he rubs it in that she shares a marriage bed with him and not me. He expresses this crudely, in ways that would outrage his wife and all of our mutual friends.

What should I do? If I reveal his vulgarities, he would deny them. If I did something like record them, everyone would think me ugly-minded. He’s been doing this a long time now. What is the polite thing for me to do?

GENTLE READER: Avoid being alone in his company. If you cannot and he continues, excuse yourself saying, “Forgive me. I am sure that our respective wives would highly disapprove of this conversation. You will understand if I take my leave and spare them.” This gives you credit for threatening him, without actually doing so.

DEAR MISS MANNERS: My husband recently threw me a surprise 40th birthday party at a local establishment we frequent. Several friends were in attendance and had braved bad driving conditions to share in the 9 p.m. celebration.

The party was a complete surprise and I had an unforgettable time. I would like to be able to say it was an absolute success. However, the delight I was still basking in the following day was cut short when I talked to my mom. My husband had not invited my parents because he did not think they would attend, due to the party not starting until later. In addition, no other family were in attendance, and the invitation was created via social media, which my parents are not part of.

My parents are very hurt, feel slighted by my husband and said it should have been up to them to decide if 9 p.m. and poor road conditions were enough to keep them home.

Up until now, my parents and husband have had a loving relationship. My husband realized his error and took it upon himself to contact my parents to extend a sincere apology, but my mom is one to hold grudges. I am very saddened to see my parents so upset and feel like I am caught in the middle. How do we move forward?

GENTLE READER: Groveling. Or rather, ask your husband to grovel.

Have him issue another heartfelt apology, this time in writing, and follow up with your parents by telling them how devastated he is, and that he has sworn he will never make a similar assumption again.

Ask them if, in the name of peace in the family, they could possibly forgive him. If there are children -- or the prospect of children -- Miss Manners recommends you invoke them for maximum effect. These are desperate times.

(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: Last summer, my sister-in-law’s best friend and her daughter moved in with her and her family. No one is sure how long this arrangement is going to last, but it looks like it will be a long time.

What is my husband’s and my obligation to this friend and her daughter for holidays and get-togethers? Last Christmas, we bought the little girl a gift because we didn’t want her to feel left out while we were giving gifts to our niece and nephew. The friend and her daughter ended up leaving for Christmas to visit family, but we left the gift anyway.

The latest problem happened when I was planning a surprise birthday party for my husband. I chose not to invite the friend, mainly because my husband does not care for her and I was trying to keep the guest list intimate since I was having the party at a restaurant.

When I sent the invitation to my SIL, she asked if her friend and daughter could come. When I told her about my budget, she insisted on their coming and paying for both. I didn’t want to cause a rift, so I ended up caving and agreeing.

After the party, I talked to my husband about what happened. Even though he agrees with me, he thinks we are just going to have to invite this friend to things, even if we don’t want to, just because she is living with his sister.

If this friend was not living with my SIL, we would never even think about inviting her. My husband has known this girl for years, but he doesn’t care for her, and neither do I. How do we handle future situations? Or am I in the wrong, and we should just suck it up and include them?

GENTLE READER: Although etiquette often uses misdirection to spare people’s feelings, it does not do so indiscriminately. (While Miss Manners’ point is that misdirection should not be used thoughtlessly, she admits that etiquette is also not indiscriminate about sparing people’s feelings.)

When you framed the problem as one of cost, your sister-in-law insisted on paying. You cannot blame her for your unhappiness that she solved the problem you gave her.

The solution is not to invent a problem that you think she will be unable to answer (“We have not invited any children and the restaurant is not really equipped to handle kids”). Rather, it is to tell the truth. Discriminately.

This means informing your sister-in-law that, while you would love to do something with the larger group at some unspecified later date (and with an unspecified host), this event is only for your husband’s oldest and closest friends and family. Discrimination comes in by omitting the part about his not liking the live-in.

There is no polite way to avoid your sister-in-law’s live-ins when you are a guest in her home, and you were right to purchase a present for the little girl. However, the obligation is conditional on the daughter’s presence: You could have asked beforehand if they would be there for Christmas.

(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 is it OK to ask someone to wash their hands after using the bathroom, because you could clearly hear that they did not?

I have been operating under the assumption that if I am in someone else’s home, I have no right to ask them to do something differently. Is it only OK in my own home? Or if they are in the midst of preparing a meal we are both going to eat?

What if you ask them to go back and wash their hands and they say they already did, even though you know they didn’t?

This is all happening with a male relative whose home I occasionally visit. Last time I was there, he also went to the bathroom with the door open.

I’m constantly telling myself, “It’s his house, you can’t ask him to change.” It is starting to wear me down and I don’t know what to do. I know I have the option of just not going to his house, but I enjoy spending time with him.

GENTLE READER: Doctors have a saying about what color the world would be if certain common, but unhygienic, substances had discernible colors. We are all faced with unhygienic conditions much more frequently than we care to know.

Those who are faint of heart should not read about backstage in the restaurant business. The question, then, is what to do for those whose sensitivity to such conditions cannot be answered by etiquette’s first rule in these cases -- namely, “out of sight, out of mind.”

The location -- your home or your relative’s -- is unfortunately irrelevant: It is impolite to correct another person’s manners. The closeness of the relationship does matter, as a spouse or sibling can say things in private that are barred to an acquaintance. Miss Manners therefore recommends seeking out such a third party to whom you can, with apologies, share your discomfort, in the name of the offender’s health as well as in the hope that he or she will intervene without naming you.

DEAR MISS MANNERS: IS IT APPROPRIATE TO HAVE A GOFUNDME PAGE TO PAY FOR YOUR HONEYMOON?

GENTLE READER: NO.

DEAR MISS MANNERS: After the death of one of their grandparents, my relatives, for the second time, have opted to use the postage that would have been spent on thank-you notes to make a donation to a group of cloistered nuns. One of the relatives in question is a member of the convent.

Is this something new, for people to donate to a cause or charity to which the giver would not choose to give?

GENTLE READER: It may be, which does not mean Miss Manners condones the behavior. Were the subject-matter not so serious, she would express amusement that the relative chose a cause that directly benefited herself; that the cause in question is supposed to be dedicated to doing charity for others; that the amount saved on postage must be insignificant -- and that, lacking a note explaining the action, no one is ever likely to know why their condolences were so rudely ignored.

(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.)