Q. I'm a 33-year-old, divorced attorney and have no children of my own. My boyfriend has two sons, ages 6 and 11, who live with us half time. My boyfriend and I have known each other since junior high and have a strong relationship, and the boys and I have wonderful relationships as well. I help them with homework, taught them how to ride their bikes, and I taught the younger one how to tie his shoes and how to read.

My boyfriend's ex-wife, however, isn't happy with the situation. She and my boyfriend have very different parenting values. A great deal of emphasis and encouragement is placed on school and learning here, and the primary concerns at their mother's house are sports and video games. The older son gets poor grades in school. According to the underachievement quiz that I found on your website, he has serious problems in every category.

Coming from a broken home myself, I'm acutely aware of the problems and hardships that come to children as a result of differences between parents. I'm very concerned for the boy, and I'm unsure how to navigate in these waters. His mother continues to sign him up for extracurricular sports (although he doesn't seem to enjoy any of them and doesn't exert much effort), while his grades are slipping.

I've heard her lie to his teachers for him when he fails to turn in assignments. She admits that she makes fun of my boyfriend for assigning the boys homework over the summer and being too concerned about their hygiene and appearance. She yells, swears and belittles my boyfriend in front of the children and has recently begun to threaten to take the children from him and "teach him the hard way" by filing a criminal complaint for harassment against him. The situation is stressful for me, so I'm sure it's ten times as stressful for the boys.

When faced with this sort of situation, how does one proceed? We're concerned that the older boy has already learned to take the easy way without repercussions. His mother believes it's unfair to him to take away sports or video games and refuses to do either. We're also concerned that he'll lose self-confidence as he fails in school. How can we help him to feel safe and secure while motivating him to achieve the grades that he's capable of without seeming too harsh and rigid?

A. Although you're not legally a stepparent, you're serving in that role and I view your situation as difficult, but not impossible. Your stepson can reverse his underachievement even without you taking sports and video games away, since he'll soon look more and more toward a loving father for priorities in his life. Try not to belittle his mother, but have his dad set a structured schedule for homework when he's with you. Be sure he encourages him, and even helps him, so that he views this as his dad's priority.

Take an interest in his sports as well, but designate video-game time only after homework is done and checked by his father. Arrange for regular communication with his teacher, and stay patient and consistent, emphasizing hard work and effort more than grades.

Explain that his brain is a muscle that will get smarter as he exercises it more, but it won't stay as sharp if he doesn't do his homework. I'm guessing that he'll gradually make progress even without his mother valuing his progress, and when he does, she'll be mighty proud of his improved grades as well.

For free newsletters about "Why Bright Kids Get Poor Grades" or helping children cope after divorce, send a large self-addressed, stamped envelope to P.O. Box 32, Watertown, WI, 53094, or read ?Helping Your Children Cope With Divorce? at www.sylviarimm.com.

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.