DEAR ABBY: My daughter is annoyed with me because I’m not jumping up and down with joy over my grandson’s forthcoming wedding. Yes, I am happy they’re getting married, but how excited can I get? The two have been sexually involved since they met in high school four years ago. She was 16; he was 17. For the past two years, he and his girlfriend have shared an apartment and lived as man and wife. The bride-tobe’s parents are not exactly thrilled either at the expense of a white gown and a few hundred chicken dinners, hall and band. However, my daughter insists on it and wants everybody to get excited. OK — so I’m excited. Whoopee. GRANNY MAE

DEAR GRANNY MAE: You are focusing on the wrong thing. Your grandson and his fiancee care enough about each other to commit, in a public ceremony, to spending their lives together. That’s a positive step that deserves to be celebrated. Whether you or I approve of couples living together is beside the point. They are adults and it was their choice. Be happy that they are now tying the knot to bind themselves together in a more permanent union.

DEAR ABBY: My sister, “Doris,” got divorced 10 years ago. Since then, she’s lost a lot of weight and had extensive plastic surgery. She now dresses in as little clothing as possible to show off her body.

We frequently have family get-togethers, and I notice my husband, “Rod,” looking at Doris in a sexual way. She seems to appreciate it. At the last family gathering, she wore black thong underwear. I know because it became impossible to ignore after she positioned herself on her chair so that her pants dropped down, exposing her fanny.

I am upset with her. I told my mother I’d like to limit these get-togethers. Now my mother is mad at me. She says I am being silly and unreasonable. What do you think?

HURTING IN SAN FERNANDO VALLEY

DEAR HURTING: Your sister is overcompensating for all those years she felt unattractive. I hope she learns quickly that the kind of attention she’s getting from dressing so seductively isn’t the kind that lasts. P.S. In the interest of your marriage, your husband should be less obvious about his ogling since it’s making you feel insecure. If you haven’t done so already, please mention it.

DEAR ABBY: My daughters attend a high school where a “Sadie Hawkins” dance has been planned for the students. The problem is, the guys at their school think it’s “cool” to wait until the day before the dance to answer the girls’ invitations. These are otherwise polite young men, but they see no problem in making the girl wait until the last minute to know if she even has a date for the event. I think this is extremely rude and inconsiderate. What is your opinion? And what do you suggest the girls say to the young men who leave them hanging? MOM WHO CARES IN ARIZONA

DEAR MOM WHO CARES: The courteous way to respond when invited out is to accept or say no PROMPTLY. I agree that it’s rude to keep someone hanging. If your daughters don’t get a response within a reasonable amount of time — say, 24 to 48 hours — they should invite someone else. And when the original boy finally comes up with his acceptance, he should be told, “Sorry, when I didn’t hear back from you, I asked someone else.” Write Dear Abby at www.DearAbby.com or P.O. Box 69440, Los Angeles, CA 90069.