DEAR ABBY: My husband, "Dan," and I have been married for 10 years. We are childless by choice and happy with our decision. Recently, at a family gathering, Dan's sister put us on the spot by asking us to be the guardians of her two small children should anything happen to her and her husband.

Dan agreed without discussing it with me, and I was furious. The whole thing made me very uncomfortable. We talked it over, and Dan confided that he wasn't comfortable with it either. However, he thinks we shouldn't worry about something that probably won't happen.

Abby, if something DID happen to my sister-in-law and her husband, it certainly wouldn't be the right time to announce that Dan and I had changed our minds about caring for their kids. Dan and his sister come from a large family, so there's no shortage of more qualified candidates.

What should I do? Should I go along with my husband on this or put a stop to it now? -- RELUCTANT GUARDIAN ON THE EAST COAST

DEAR RELUCTANT: You and your husband MUST tell his sister and her husband that after giving it careful thought, you are unable to make the kind of commitment for which they are asking. Explain that you are honored they asked you, and will make sure the children are provided for -- but you cannot be the primary caregivers.

DEAR ABBY: I am a 33-year-old mother of two little girls and a teenage stepson. This is my second marriage. It has lasted eight unhappy years, but I've stuck it out. My husband and I went to counseling and tried all the things you do when a relationship is failing; nothing has worked.

Recently, I started calling "Paul," my high school sweetheart, and things are blooming. We are both unhappy in our marriages. We have told each other we don't want to give up what we have -- only because we're both secure and comfortable.

Paul and I haven't seen each other since we were 18. (We live on opposite coasts.) So far, all we've done is talk on the phone, but things are definitely heating up. What now, Abby? -- UNHAPPY EAST COAST WIFE

DEAR UNHAPPY WIFE: Now it's time to realize that you are no longer 18 -- and teenage romances are highly idealized. It is also time to tally up what you both have to lose, should this progress into an affair. Before you make an irrevocable mistake, and in fairness to both of your spouses, go to another counselor and try to get your marriage back on track. This may not be what you want to hear, but it's the best advice I can offer.

DEAR ABBY: I am a 33-year-old mother of two little girls and a teenage stepson. This is my second marriage. It has lasted eight unhappy years, but I've stuck it out. My husband and I went to counseling and tried all the things you do when a relationship is failing; nothing has worked.

Recently, I started calling "Paul," my high school sweetheart, and things are blooming. We are both unhappy in our marriages. We have told each other we don't want to give up what we have -- only because we're both secure and comfortable.

Paul and I haven't seen each other since we were 18. (We live on opposite coasts.) So far, all we've done is talk on the phone, but things are definitely heating up. What now, Abby? -- UNHAPPY EAST COAST WIFE

DEAR UNHAPPY WIFE: Now it's time to realize that you are no longer 18 -- and teenage romances are highly idealized. It is also time to tally up what you both have to lose, should this progress into an affair. Before you make an irrevocable mistake, and in fairness to both of your spouses, go to another counselor and try to get your marriage back on track. This may not be what you want to hear, but it's the best advice I can offer.

DEAR ABBY: My husband's parents are wonderful people whom I've grown to love in the 12 years I've been married to their son. The problem is, every time we go out to dinner or stay overnight somewhere, they insist on paying for everything.

My in-laws have three grown children with good jobs. But every time the check arrives, it becomes a major fight.

Last weekend, my husband and I took his folks on an overnight trip for their anniversary. They knew ahead of time that it was our gift and we were going to pay. However, when we checked out, the desk clerk told us the rooms had "already been taken care of."

How should we handle this in the future, Abby? Should we give up and allow Mom and Pop to pay all the time? -- TIRED OF IT IN POMPANO BEACH, FLA.

DEAR TIRED OF IT: Probably. Your in-laws regard you and your husband as "the kids." They can afford it, and they still see their role to be providers. I'm sure they mean no offense, but they probably don't realize how heavy the burden of gratitude can weigh after a while. Since you cannot change them, rather than cause a scene, accept graciously and let it go.

DEAR ABBY: Three months ago, my longtime boyfriend, "Mark," broke up with me. We had planned to be married. It took me a long time to get back to being my old self.

Right after our breakup, Mark began dating his boss's daughter. I'll call her "Carrie." I accepted it because I care about Mark and want him to be happy.

My problem is, for the past month, Mark has called me frequently in the middle of the night to tell me he "misses me" and how much he "continues to love me." He's even said he still wants to marry me.

Every time Mark calls, he invites me to come over and sleep with him. I have refused because of Carrie. I feel sorry for her.

Abby, I cannot imagine being with a man who is still in love with someone else. Should I tell Carrie what Mark is up to -- or should I stay out of it? I am awaiting your reply. -- MARK'S EX

DEAR EX: The first thing you should do is fall on your knees and give thanks that you are no longer engaged to this two-timing user. If you are wise, you will stop all contact with him. That said, if you try to warn his boss's daughter, she will probably interpret it as jealousy and not believe you. She needs to find out about him on her own. And when she does, Mark will be looking for another job and another gullible woman.

DEAR ABBY: Our family recently attended my daughter's high school graduation. Seated next to us was a couple who talked to each other during the entire commencement -- until the man's cell phone began ringing. Then he continued to carry on a loud conversation over the phone. Needless to say, it was a major distraction for all of us who were seated near him.

This is not the first time such a thing has happened, and I know it won't be the last. People who talk while others are trying to listen do not seem to care that they're disruptive and disrespectful.

This happens everywhere nowadays -- church, business meetings, movies and plays. Growing up, I was taught to listen with respect and never interrupt others.

I have tried to politely ask the offender to "keep it down," or have gotten up and moved to a quieter location, but sometimes it's impossible.

Has our society gotten so "me-oriented" that we've forgotten the common courtesy of being quiet while others are speaking? Maybe you or your readers can share what works for them in order to stay calm during situations like this. -- LOSING MY COOL IN LYNCHBURG, VA.

DEAR LOSING MY COOL: Cell phones are a boon to many people. But used thoughtlessly, they also create very real problems. Of COURSE people should observe the rules of common courtesy and turn them off at public events. And people who converse on their cell phones in public places should remember to do so discreetly -- not only because to do otherwise is inconsiderate of those around them, but also because they can unwittingly reveal personal information that could come back to haunt them.

To order "How to Write Letters for All Occasions," send a business-sized, self-addressed envelope, plus check or money order for $5 (U.S. funds) to: Dear Abby -- Letter Booklet, P.O. Box 447, Mount Morris, IL 61054-0447. (Postage is included in the price.)

DEAR ABBY: Somewhere in this great country there's a town or city that will win $25,000 and national recognition by entering the National Organization on Disability's 2003 Accessible America contest. Anyone who feels that his or her community is a model of accessibility -- a place where people with disabilities can fully participate just like anyone else -- should encourage the mayor to enter the contest before the Oct. 31, 2003, deadline.

When communities make the commitment to improve accessibility, all of their citizens and visitors benefit. One-fifth of all Americans have some sort of disability. That's why it is crucial that communities ensure a safe and welcoming environment. The Accessible America contest puts a spotlight on those cities and towns that are leaders in improving the quality of life for people with disabilities.

As vice chairman of the National Organization on Disability (NOD), I urge mayors in towns large and small to place a priority on creating a level playing field for all citizens by providing equal access to their services and facilities. I encourage them not only to share their successes by entering the contest, but also to join NOD's Community Partnership Program on behalf of their constituents. It's a great way to learn how best to comply with the Americans With Disabilities Act and to get tips on maximizing access and opportunities. -- CHRISTOPHER REEVE

DEAR CHRISTOPHER: Count me among your many fans. I'm pleased to publicize such a worthwhile endeavor.

Readers, the NOD Community Partnership Program is sponsored by the Alcoa Foundation, and the Accessible America contest is sponsored by UPS. I salute both for their community involvement.

To learn more about the contest, call (202) 293-5960 or visit the NOD Web site: www.nod.org. I'll put the name of the winning entrant in my column in December.

DEAR ABBY: I am 16 and attending summer school. My sister, "Maria," is a year older than me. She's new to our school because she just moved here to live with our mom and me. (She was living with Dad, but he kicked her out.)

Since the day Maria set foot on campus, every guy here is after her -- and I know why. She wears skimpy clothes and has a big chest.

Now every boy I like ends up liking Maria instead of me. I'm sick of it. There's only so much a person can take, and I've reached my limit. Do you have any advice for me, Abby? -- EXASPERATED IN NEW MEXICO

DEAR EXASPERATED: I'll begin with some words for your mother, because she is the person who is going to have to deal with your sister. There is a time and a place for everything. Maria is crying out for attention, but she's getting the wrong kind -- and unless there is intervention, she'll wind up in trouble. Your mother should make it her business to find out what is proper attire at your school and enforce the dress code.

Now, some advice for you: Sibling rivalry is normal -- the attention your sister is attracting is transitory. Concentrate on your grades and on activities at which you can excel. That way, you'll be an outstanding individual in your own right and not just "somebody's sister." Trust me, it'll pay off in the end.

P.S. Please clip this column and show it to your mom.

What teens need to know about sex, drugs, AIDS, and getting along with peers and parents is in "What Every Teen Should Know." To order, send a business-size, self-addressed envelope, plus check or money order for $5 (U.S. funds only) to: Dear Abby, Teen Booklet, P.O. Box 447, Mount Morris, IL 61054-0447. (Postage is included.)