Q: I’m 25 years old and a single mother. I’m facing a complicated situation. Two years ago, I met a man and thought we fell in love. He was 48 and told me that he was divorced. Neither of us was planning on a child, but I got pregnant. I was going to school and he didn’t want children.

I told him I wanted to keep the baby and didn’t expect anything from him, but if he decided to get involved in the child’s life, it would be great. As time went by, he seemed happier about the child and told me it was the best thing that ever happened to him. I believed him.

When I was eight months pregnant, he told me he was seeing another woman. I freaked out, and my world suddenly turned upside down. We were living together, had plans to get married, and I never suspected anything. The other woman was already three months pregnant and didn’t know about me. He also admitted that he wasn’t divorced.

To make things worse, he brought the other woman to live with us in our one-bedroom apartment to share the same bed. Everything he’d told me and done with me, he had done with her, too. She even looked like me. It’s impossible for me to comprehend this behavior.

We’ve both had our babies. We don’t live together anymore, but now he spends one weekend with me and the other with her. He takes care of both children and makes sure we both have all we need.

I’m very confused and scared. I don’t know what I’ll tell my daughter when she grows up and asks questions. No matter how hard I try to figure it out, I still don’t know what to do. I thought it would be best for her to know about her father. He loves her very much and is attached to her.

Do you think there’s a good way out of this? I’m afraid for the emotional and mental stability of the children. What would be a good way to tell my daughter about this complicated situation? He won’t marry either of us because he’s already married. He doesn’t want to change anything. I would appreciate advice.

A: Your story wins the prize for complicated lifestyles. You’re 25 and have your whole life ahead of you, and while it’s convenient that your child’s father is supporting you and your daughter, you need to plan a future for yourself and your child. There’s no reason for you to continue your personal relationship with him. If he’s paying child support, your daughter deserves that. Her father can visit with her and take her places. It’s time to separate the two relationships.

Go back to your plan to study to find a career. Your child can attend day care while you prepare to support her. You can meet younger men who are looking for real relationships. You need to give up on your relationship with this man who lied to you.

As for your daughter, she knows her father, but you can explain as she gets older that you aren’t married. You can tell her that she has a half-sibling that she’ll meet when she’s older, but since the child lives elsewhere, the child can’t be part of her life now. Unless you’re willing to live in a harem, you need to put this mistake behind you. Look toward the future for a man who truly wants to share your life, so your daughter and future children can have a real family life.

I hope you have family and friends nearby for support. You should surely get counselling to help you through this difficult time.

Dr. Sylvia B. Rimm is the director of the Family Achievement Clinic in Cleveland, Ohio, a clinical professor of psychiatry and pediatrics at the Case Western Reserve University School of Medicine, and the author of many books on parenting. More information on raising kids is available at www.sylviarimm.com.