DEAR MISS MANNERS: There are many examples of technology and bad behavior merging, and I ask for your opinion regarding one that bothers me: people locking their vehicles by pressing the key fob twice, which causes the vehicle to omit a loud chirp.

All one has to do to lock a car is push the button inside the door, or at most, push the fob once, which doesn’t cause a loud noise. In parking lots and garages, these unexpected loud noises can startle people, and in residential areas, they can awaken sleepers.

This practice shows a lack of concern for others. Also, I don’t understand the motivation: Is there some small sense of power the person gets from using the technology?

GENTLE READER: Yours is an excellent example of technology inviting bad behavior. Why could not the engineers simply have made the device vibrate and/or light up when locking the door?

But Miss Manners cannot condemn people for using this technology, and she does not share your mystification about why people press the button more than once. She doubts there is any sense of power gained from using this tool, but does understand its marginal ability to assuage the sense of powerlessness about whether the door has actually been locked.

Plus, it can help locate a car in a crowded and poorly labeled parking lot.

DEAR MISS MANNERS: I stopped eating potluck food at work years ago when I found cat hair in a piece of cake. Apparently, the lady who brought the cake regularly let her cats jump up on her kitchen counter. I was always careful with food before that, but that was the last straw.

I was invited to a co-worker’s home for dinner recently, but declined going. I had been there before, and the kitchen was very dirty, and there was a big fat cat roaming around.

I think people feel snubbed when I tell them “Thanks, but no thanks” when they offer me food. Another example: The lady downstairs is a heavy smoker and drinker. When she calls me up and asks if I would like some of the food she has prepared, I always find an excuse to decline. She seems miffed about it.

At an event in a park, a lady I did not know had a big bucket of cookies and was offering them to people. I almost took one, asking her what bakery she got them from, and she said she made them herself. I withdrew my hand and told her “No, thanks” and she got angry at me.

I don’t want to sound snobby, but how do I politely get out of these food offers?

GENTLE READER: You also do not want to waste food, nor do you want to be dishonest -- by, for example, saying that you already ate.

Miss Manners can accommodate this long list so long as you do not also insist on being original: Say “No, thank you” -- this, time before reaching for a cookie -- and repeat it as many times as necessary, resisting the temptation to explain your reasons.

(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: My teenage son had begun seeing a new neurologist, who is highly recommended and seems to be very skilled. We have had two appointments with this doctor, and both times, he used at least a half-dozen swear words in the 20-minute appointment.

He’s young, very friendly, very informal, and probably thinks it’s no big deal because my son is a teenager. He works for the pediatric hospital, and I’m hoping he doesn’t use the same language when giving medical care to young children!

But it’s very uncomfortable for me, and my son agrees that it seems strange. It seems so inappropriate for a professional person!

Of course I’ve heard all these words before, but I don’t enjoy hearing casual swearing. I missed my chance to say something in the appointment. We’ll see him again in six weeks. Is there a way to bring this up respectfully?

GENTLE READER: At the next appointment, ask to speak with the doctor first while your son remains in the waiting room. Then tell him that both you and your son appreciate the work he is doing, but that you (and the boy’s other parent, if applicable) ask that he not use swear words during appointments. Tell him that you are trying to set a different example for your son.

The doctor will conclude that you have no sense of humor or concept of the modern world. This is fine, so long as he understands that you mean what you say -- and that you are the customer.

You and your son can have a laugh about it in the car afterwards. He will have been in the waiting room during your discussion with the doctor not because he cannot know what is happening, but because it will help convince the doctor that you are serious.

DEAR MISS MANNERS: While having dinner at a five-star restaurant, he took out 15 assorted vitamins and supplements, placing them on his bread plate. Then he used his dinner plate for the buttered bread.

Taking supplements is fine, I just feel there’s a better way than lining them up on a plate at a restaurant.

When the server offered dessert, he stated, “I’m too full, but I’ll have a bite of yours.” I made light of it, saying, “No, I’m not sharing. It’s all for me,” and everyone laughed. He was serious, and would’ve sampled it, I’m certain. How to handle?

GENTLE READER: Pronouns are so much more helpful when they are attached to clear antecedents.

That the "he" in question was near enough to reach your dessert suggests anything from a husband to a boyfriend to a blind date to a dinner partner. Your certainty that he was serious about sampling your dessert implies you do have some uncertainty -- and therefore indicates a more casual connection.

This being so, Miss Manners agrees with handling him as you did, which is that his boorish behavior with the vitamins is his own concern, but he must keep his hands off of you and yours.

(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 attended a bridal shower where the bride-to-be asked for “no gifts, please.” Half the attendees showed up with gifts anyway, and the ones who honored her request and didn’t bring a gift were left to feel cheap.

It was awkward for everyone, including the bride-to-be, who wasn’t sure if she should open the gifts or not. What should she have done?

GENTLE READER: This is why Miss Manners keeps rejecting this frank and seemingly simple way of avoiding receiving presents: It doesn’t work.

Some people simply ignore it. Others interpret it as a coy prompt to be sure to give presents, or as a request for cash instead of goods.

It creates a burden on the gift recipient, who must then protect the guests who respected her wish from feeling that they were in error.

The bride should absolutely not have opened the presents in front of them. She should have briefly thanked the donors, put the unopened packages aside, and written her thanks after opening them privately.

But doesn’t anyone realize that, by definition, showers feature presents? So do birthday parties. Surely this accounts for the problem guests have with these gift bans. Can’t friends gather without applying those labels?

DEAR MISS MANNERS: I’m a cashier in a grocery store, and we’re required to wear a name tag with our first name printed boldly.

It feels creepy when customers, often the male ones, address me by saying my name in a domineering way. I’ve tried taking a deep breath to resist the urge to say something insulting, but I really wish I knew how to respond.

I resent being spoken to by a stranger this way, especially when I’m trying to be of service. Any suggestions for me?

GENTLE READER: Address your supervisor. That is, mention the problem while offering a solution: workplace pseudonyms.

Miss Manners can imagine your having fun with this. “Cashie the Cashier,” perhaps?

After all, the real purpose of name tags in commercial situations (as opposed to your school reunion, when faced with your inexplicably aged classmates) is for the rare case when the customer needs to identify you: “In the aisle, Ryan told me this was on sale, but now Lila tells me you have to buy three cases to get the discount.”

DEAR MISS MANNERS: When I am invited to stay in someone’s home, and that home isn’t very clean, may I leave it cleaner than I found it?

I assume that my hosts are already overwhelmed and I wouldn’t want to add to their stress by impugning their housekeeping. It would be a nonissue for me to clean a bathroom (sweep the dust and hair from the floor, wipe down the countertop and mirror, etc.) or to remove the exploded spaghetti from the inside of the microwave before I warm up my coffee.

Would that count as being a good guest, or as being judgmental?

GENTLE READER: Your choice. A good guest would do this so quietly that the hosts might even think that they had left things cleaner than they supposed. A bad one would make sure that they knew.

(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.)