Q: My dinner date and I were contemplating what size bottle of wine to order. He wanted to order a full bottle of wine and take home what was left in the bottle. I would be terribly embarrassed by this. Could you please tell me if taking leftover wine home in a doggie bag is poor etiquette?

A. It is certainly poor nutrition for your dog. The only way to retain ownership of excess restaurant wine besides forcing it down your throat, is to compliment the restaurant manager lavishly and inform him that you will be back for another delicious meal and would like to have "your" bottle placed then on "your" table. This can only be done in very cheap pensions or in very expensive restaurants. If you go to ordinary restaurants, it would be best to adjust the size of your eyes to the size of your bladder, and then order half bottles or house wine by the glass.

Q. With Mother's Day coming up, I would like to know who is responsible for buying gifts for the stepmother of small children. My sons are "four-parent" children living with their motehr, but very much in contact with their father and stepmother. I have, in past years, provided gifts for their stepmother and grandmother, from them, for Mother's Day.

Is this the proper thing for me to do? Do you have any suggestions to help ease the edge of inflation in regard to these "special days"?

A. You have missed the pont about Mother's Day presents on two counts, and both of these mistakes are costing you money.

1. The present should be provided by the child according to his ability. Naturally, if you are providing your former husband's second wife with a present appropriate to your income level it is going to cost more than if the child, assessing his allowance, chooses, say, a sachet or a prettily wrapped chocolate.

2. The most appropriate presents for such occasions are made, not bought. This is therefore a marvelous opportunity for you to encourage your child to choose presents from among the wealth of refrigerator art, ceramic what-nots and two-inch square woven pillows that every parent with custody has around the house.

Q. Please tell me how one goes about wrecking the nerves of the host of a party to which one has not been invited. It is of note that the host was recently given a party in his honor in my home. Of course, I wish to appear as magnanimous as possible.

What is an appropriate remark, if any, to make when unexpectedly running into the host? If I am planning a party in the near future, should the host be invited or not? What is an appropriate reply if asked if I know anything about the letter in "Miss Manners"?

A. If you want to be magnanimous, you will assume that the party you heard about was not considered sufficiently grand by its host to be the one to repay you for your hospitality and that he is saving up to be able to do this in appropriate style.

However, you did not say this; you said that you wished to appear to be magnanimous. The remark on meeting unexpectedly could be, "Oh, I've heard your apartment looks just beautiful now. I'd love to see it some time." The invitation to your next party could be issued by saying, "Do come -- I know you don't have much time to entertain, but I'd love to see you." The reference to this column should elicit the remark, "Oh, I can't believe anyone would do that."