Dear Annie: We are close friends with "Allen and Michelle", who live just down the street from us. We share a lot of personal information with each other and enjoy hanging out.The problems began after Michelle introduced us to "Sandra and Joe". Sandra made several comments about getting together with us, so finally, I called to invite them out for dinner and drinks. When Michelle found out we had been out together, without her and Allen, she was very upset. Yet that same night, she and her husband had a prior engagement and couldn't have come anyway.

We are struggling with Michelle's possessive attitude and fear it will break up all of the friendships. We are not in grade school anymore. How can we resolve this and act like adults? — New Friend>Dear FriendsB>You may not be in grade school, but the reaction is the same. Michelle is jealous that you and Sandra are friends without her involvement, and when you plan evenings that don't include her, she feels as if she were tossed from the popular girls' clique. A more mature person would, of course, hold those feelings in check. You need to reassure Michelle that you like her as much as Sandra, and you do this by spending time with her, with and without others. You also should tell Michelle directly that you value her friendship and you hope next time you get together with Sandra, she will be available to join you.

Dear AnniI would like to know the correct etiquette regarding call waiting on the telephone.

I have a good friend who, when she gets a call waiting beep, promptly hangs up with me and takes the new call instead of telling that person she will call them back. What do you think? — Florida Fan

Dear Flori Etiquette says the person you are already on the phone with takes precedence over any incoming calls, unless they are of an urgent nature. Your friend should tell the person who intrudes that she will call them back. However, there's always the remote possibility that your conversations last a little longer than your friend prefers and she is looking for a reason to get off the phone.

Dear An: As a married man, I was disappointed by the column you printed with a series of responses regarding a wife's lack of desire for sex.After a frustrating time in our relationship a few years ago, my wife and I attended counselling and a couples' retreat at our church. As many of your readers suggested, my wife said if I helped more around the house, she would have more energy for sex. So, since then, I have taken over the majority of the housework, do all the laundry, grocery shopping and cooking, but still I am nearly celibate. I have carried out my part of the bargain, but we have sex less than once a month.

Because of my wife's frigidity, I have started an ongoing sexual relationship with a woman I met on the Internet. It's sex only, and very good sex, but I still desire a full marital relationship with my wife and my patience is reaching its limit. If my wife maintains her distance, I'm out of here. Let this be a warning to your female readers — if you don't provide regular sex with an effort at passion, your man will seek it elsewhere. —ackDearck: A lot of women don't like to hear that, but it's true. Most men need sexual intimacy on a regular basis, and they prefer to have it with their wives. Women who deny sex to their husbands can lose the relationship. Meanwhile, has your wife had a complete check-up? Sometimes a lack of desire is a treatable medical problem. We hope she will consider it for the sake of her marriage.

Annie's Mailbox is written by Kathy Mitchell and Marcy Sugar, long-time editors of the Ann Landers column. Please e-mail your questions to anniesmailbox@comcast.net, or write to: Annie's Mailbox, PO Box 118190, Chicago, Illinois611.