(Nick Galifianakis/The Washington Post)
Advice columnist

Dear Carolyn: My 15-year-old son and his stepmom, my wife of eight years, have developed such a contentious relationship that I don't know what to do anymore. He's not a bad kid but has a history of lying about grades, schoolwork and some really silly things like cleaning his room.

I've been disciplining him for years now. Grounded, do chores, etc. She takes the fact that I can't eradicate the lying as a failure of my parenting and creates situations all the time where they fight. They basically hate each other.

I've tried to get her to tell me when she wants him to do a chore or something, at least for a while, so maybe we can avoid the conflicts. She won't.

So it pretty much tears us apart. She blasts me when I get home about their problems during the day, and I get upset and am basically a worse parent at times because of it. My younger son, 10, is her baby, another great kid, and they never have problems.

I love her very much, but I'm not sure how to make this work. I'm sure she would be happy if I gave up custody of him, which is something I won't do. I've asked her point-blank what she wants me to do, and she doesn't have the answer.

— Anonymous

Anonymous: As described, your wife’s behavior is a stunning failure of adult self-control.

Your son’s lying is a serious problem, for sure. However, he isn’t only still a child but also one in an insecure, emotionally unsafe home environment. This is the basic recipe for a child who acts out.

I also don’t minimize the difficulty of being a stepparent, especially of a child whose dishonesty has jumped its developmental boundaries. But she arrived before he was 7! And her response is to “blast” you, resent your custody and pick fights with him? Just, no.

As the parent ultimately responsible for his emotional health, you cannot abide this.

Your whole household is overdue to be placed in the lap of a reputable, carefully chosen family therapist — including the “never have problems” kid, and not just as an afterthought. He no doubt is deployed as tacit or overt leverage against the troubled child, which not only hurts your older son, and not only hurts the relationship between the brothers (typically a lifeline in chaotic homes), but also hurts the “good son” himself. He sees the roiling waters around his brother; how sure are you that he’s problem free, as opposed to compensating for his environment and forcing himself to hold still?

Both boys — again, developmentally — are entitled to their chances to screw up without feeling as if they’re going to be swallowed up by their every mistake. Lying itself is a mistake, yes, but it’s also a byproduct of an existential fear of making one.

One of your boys is showing in his way, and possibly the other in his, a plain fear of doing wrong. And unless there’s more to this than you’ve given me here, it’s hard to trace that fear to anyone but your wife and her punitive ways with the older boy.

Check your insurance and health benefits. Call the pediatrician. Get some names. Get these kids — and you, and your wife — some immediate, qualified help.

Write to Carolyn Hax at tellme@washpost.com. Get her column delivered to your inbox each morning at wapo.st/haxpost.