Q: About a year ago my husband told me he had been intimate with a former business colleague while on a business trip. She became pregnant and recently gave birth.

I was devastated. I had never doubted his fidelity and love and it took several months of counseling for me to feel anywhere near normal again.

My husband and I do love each other very much and want to stay married to each other.

This action was a dreadful, one-time mistake on his part, which he regrets. We offered to rear the child, but the woman would not agree to that. My husband is paying child support.

The problem is the child's mother. They live in a different city, so distance is helping us, but she is determined that my husband should be an active father to the child.

She was upset because he didn't send a card or flowers at the birth of the child and wouldn't acknowledge several gifts we sent because I signed our given names. She expects him to sign the card "Daddy." She also expects him to come see the child.

Every demand she makes is hurtful to me. I see it as a desire on her part to continue a relationship with my husband and deny my existence and importance in his life. The child is obviously too young to care, one way or another. Because it upsets me so, and because my husband also feels her demands are unrealistic and unreasonable, he is hardening his heart to any emotional involvement with the child. This is not really what either of us wanted to do.

We have a 9-year-old adopted child. This child is bright, happy, loved and loving. We have always told our child the truth about everything and because of this woman's attitude, we feel we will have to tell the truth some day about this sibling.

What is the best course to take for the sake of these two children? I know that the wrong handling of this situation can cause severe emotional damage. I do not want that for either of them.

When should we tell our child? So far we have told only the people from whom we needed help. If we dissociate ourselves from this woman and her child, what effect can we expect that to have on the child? Or if my husband is a part-time father -- which is all he can ever be to this child anyway -- what effect will that have on the child?

A: Every new mother goes through some despair and self-pity in the early weeks, but this mother has the added burden of anger. She is furious with your husband and with herself and she's trying to make him pay. Money is clearly not enough. She demands his attention because she knows how hard it is for him to give it and still keep peace in his marriage -- and within himself. And yet, if he were adamantly claiming visitation rights -- as the law would probably give him -- she might well fight that.

Despite all the grief this mistake has caused, it was honorable of your husband to tell you about it when it happened, for marriage calls for full intimacy. A couple can't have an honest relationship if the husband or wife consciously hides a secret that affects their vows.

Most marriages can withstand such knowledge, if both partners recognize it as a symptom of their own personal and marital problems. By working to heal them, their relationship can develop a tensile strength. This takes time, however. Marriage has many peaks, but sometimes you have to climb up from the valleys to reach them.

You've still got quite a climb.

Your own anger -- and hurt and disappointment -- was inevitable, and it's probably much greater than you think. It will take more than a year and a little counseling to rebuild the trust you've lost. If you felt fully safe again, you wouldn't need to insinuate yourself into the situation by sending presents to the child and signing both your own name and his. That only gives ammunition to the child's mother, for she knows her demands are getting to you and therefore to your husband.

You need more therapy, on an individual basis, to get your emotions under control. The pain will pass quicker if you have help.

Therapy also will help you keep your secret better, especially from your child. To learn about this sibling too soon would be very confusing; it would undercut the example your husband is trying to set, and damage your child's trust in him. Perhaps, in 15 or 20 years, you may explain it, adult-to-adult -- but by then it may not seem relevant or necessary.

What the other child's mother does about this matter is out of your hands. Right now she is using the child as a weapon, which is unfair to everyone. If your husband gave attention unwillingly and on demand, he would hurt the child with his mixed messages. This involvement would also hurt your marriage, which for the sake of your own child needs to be strong.

While it would be civilized if your husband could have a relationship with this child, it doesn't seem possible under the circumstances. He would be wise to limit his contact to a financial one.

When the mother recognizes that money is the most your husband will give, she'll probably accept the situation better, even though it may take counseling for her to do it with grace. Perhaps your husband could offer her a lump sum to cover the difference between its cost and her insurance, paying the therapist directly, so the money is only used for that purpose. This should help her become a more stable mother to his child and let her get on with the business of living. In either case, she'll probably marry -- most single parents do -- although your husband would still be bound to contribute to the child's support.

Time, patience and therapy will be her greatest allies -- and yours.