DEAR ABBY: Something terribly embarrassing happened to me yesterday -- it's every young woman's nightmare.

My boyfriend's father walked in on us during a very, very private moment. We are both in our early 20s and have been dating for three years and plan to marry next year when we graduate from college.

I don't know if this was a surprise for his father since his son and I have been dating for a long time, but I am very embarrassed about the situation. How can I ever face this man again? He told his son to let me know that he was very sorry, and he didn't mean to invade our privacy. I felt a little better about the situation, but I'm still too embarrassed to look the man in the face.

Do you think he feels differently about me now? And how can I deal with this? -- EMBARRASSED

DEAR EMBARRASSED: There is nothing you can do about the past, so there's no point in agonizing over it. If your boyfriend's father is somewhat sophisticated and worldly, chances are he is not nearly as shocked as you are embarrassed. The best way to deal with it is to say nothing.

DEAR ABBY: My son was married six months ago, and I just learned that a number of wedding gifts from our side of the family have not as yet been acknowledged.

As the mother of the groom, would it be improper for me to telephone or write a note to those whose wedding gifts have not been acknowledged? -- NO CITY, PLEASE

DEAR NO CITY: Although you are understandably embarrassed, it would be inappropriate for you to take it upon yourself to acknowledge your adult children's wedding gifts.

To do so would give the impression that your son and his bride are either lazy, negligent, disorganized, insensitive, thoughtless, procrastinating or ignorant -- or possibly all of the above. It would also make you appear to be a meddlesome and overprotective parent.

But since this has bothered you enough to write to me, I suggest that you tell your son and his bride that you are embarrassed by their negligence. Then volunteer to assist in a chore that appears to be too much for them.

DEAR ABBY: Some time ago, you referred to your definition of "maturity," but you printed only part of it. Will you please print the entire definition? As I recall, it was wonderful. -- BARBARA IN KAILUA, HAWAII

DEAR BARBARA: Here it is:

MATURITY IS:

The ability to stick with a job until it's finished.

The ability to do a job without being supervised.

The ability to carry money without spending it.

And the ability to bear an injustice without wanting

to get even.

Most teen-agers do not know the facts about drugs, AIDS, and how to prevent unwanted pregnancy. It's all in Abby's updated, expanded booklet, "What Every Teen Should Know." To order, send a business-size, self-addressed envelope, plus check or money order for $3.95 ($4.50 in Canada) to: Dear Abby, Teen Booklet, P.O. Box 447, Mount Morris, Ill. 61054. (Postage is included.)

DEAR ABBY: Many years ago, I copied this poem out of your column in the Indiana (Pa.) Gazette. Since there are so many strikes now, I thought it might be a good time to print it again. -- MRS. ARTHUR STEELE, INDIANA, PA.

IF GOD SHOULD GO 0N STRIKE

by Walt Huntley

How good it is that God above

has never gone on strike,

Because He was not treated fair

in things He didn't like.

If only once, He'd given up and

said, "That's it, I'm through!

"I've had enough of those on Earth,

so this is what I'll do:

"I'll give my orders to the sun

cut off the heat supply!

"And to the moon -- give no more light,

and run the oceans dry.

"Then just to make things really tough

and put the pressure on,

"Turn off the vital oxygen till

every breath is gone!"

You know He would be justified,

if fairness was the game,

For no one has been more abused

or met with more disdain

Than God, and yet he carries on,

supplying you and me

With all the favors of His grace,

and everything for free.

Men say they want a better deal,

and so on strike they go,

But what a deal we've given God

to whom all things we owe.

We don't care whom we hurt

to gain the things we like;

But what a mess we'd all be in,

If God should go on strike.

DEAR ABBY: I am living proof that a person is never too old to learn. I have had a fingernail-chewing habit since I was a young boy. I tried everything I ever heard of to break the habit. Nothing worked -- until I read about a "cure" in, of all places, your column! You suggested wearing a rubber band around the wrist, and whenever the nail-biter picks up his or her hand to chew a fingernail, snap the rubber band instead.

Here I am, an 80-year-old man who finally found a cure for a habit I have hated nearly all my life. The rubber band I wear on my right wrist at all times is an eighth of an inch wide, and it's loose and comfortable.

I am signing my name, which you have my permission to use if you wish. Thank you, Dear Abby. -- WILLIAM (BILL) ISAKSON, HOLIDAY, FLA,

DEAR MR. ISAKSON: I am delighted to have been of help. I'd give you a snappier answer, but it might be stretching things a bit. So, congratulations, and all good wishes to you.

By popular request, Abby shares more of her favorite prize-winning, easy-to-prepare recipes. To order, send a long, business-size, self-addressed envelope, plus check or money order for $3.95 ($4.50 in Canada) to: More Favorite Recipes by Dear Abby, P.O. Box 447, Mount Morris, Ill. 61054. (Postage is included.)

DEAR ABBY: I need to know how I can legally get rid of a military .45-caliber handgun that I have had since I was in the U.S. Army back in 1943. It was issued to me prior to my being shipped overseas.

When I was discharged, the parachute and most of the other equipment I had been issued was requisitioned back by the military, but no mention was ever made of the gun, or the 1 1/2 clips of ammunition that I still possess. (In all of this time, I have never fired the gun.)

I want to return the gun to the government, but I don't want to find myself in hot water for having possessed it all this time as a civilian. Since the gun is plainly marked "U.S. Property," I am wondering if my civilian possession of it all these years may have somehow been illegal ever since my discharge. -- WONDERING IN SAN JOSE

DEAR WONDERING: According to Sherry Lawrence of the Personnel Command Public Affairs Office of the Army, the failure of the military to reclaim the weapon at the time of your discharge was probably the result of a paperwork slip-up.

Because the weapon is old and probably has not been maintained, it may be a safety hazard.

Call your local police department and explain that you have a weapon from World War II that needs to be safely disposed of. They will either advise you to bring it in, or offer to pick it up.

I advise you not to handle it -- lock it up until you either deliver it to the local police or they pick it up. Peace of mind is only a telephone call away.

DEAR ABBY: Recently we had a devastasting fire in the East Bay hills of Berkeley and Oakland. There were many lives lost -- people and animals injured, and countless homes destroyed.

In the days after the fire, the San Francisco Chronicle printed stories of personal loss. Those who were able to escape from their homes with a few personal treasures mentioned that they grabbed photographs! This brought to mind that perhaps one of the best things family and friends of those who have lost their homes can do is to go through their own personal photo collections and choose photos to give the family who has sustained this tragic loss.

Negatives can be made from photographs, and perhaps some of the local film developers could offer a discount on the process for this particular group of individuals. It would be a small way to give people back parts of their lives. -- SYLVIA CLONINGER, BELMONT, CALIF.

DEAR SYLVIA: Only a person with a generous heart would have thought of the above. Take a bow, Sylvia!

DEAR ABBY: Can you stand one more letter about tattoos?

The only difference between tattooed people and non-tattooed people is: Tattooed people don't care if you're not tattooed. -- TOM THE TATTOOED TYPESETTER, SEATTLE

Most teen-agers do not know the facts about drugs, AIDS, and how to prevent unwanted pregnancy. It's all in Abby's updated, expanded booklet, "What Every Teen Should Know." To order, send a business-size, self-addressed envelope, plus check or money order for $3.95 ($4.50 in Canada) to: Dear Abby, Teen Booklet, P.O. Box 447, Mount Morris, Ill. 61054. (Postage is included.)