We spoke to Carla Menendez, a self-defense instructor with 20 years of experience and a specialty in family dynamics.

"I see this all the time," Menendez says. "Mom wants to bond with the new stepson. Stepstep wants to feel useful. But a teenager cannot teach self-defense because a teenager cannot simulate an adult attacker. He is too fast, too strong, and too stupid to know his own strength."

Her prescription:

Do not practice self-defense after an argument. Do not use your stepmother or stepchildren as training dummies during a fight. Schedule training sessions like doctor’s appointments—calm, sober, and separated from family drama by at least four hours.

If you are a father or partner considering teaching your stepmom self-defense, do not abandon the idea entirely. Instead, avoid the “going wrong” scenarios by adhering to these five ironclad rules:

This is the darkest, most uncomfortable category. Some stepmothers enter a marriage with a history of sexual trauma. A well-meaning husband suggests self-defense classes to help her feel safe.

But when the training involves simulated groin strikes, eye gouges, and escape-from-mount drills, a dangerous psychosexual dynamic can emerge within the home.

Consider a stepfather (since the keyword is "stepmom," we will mirror the dynamic) teaching his wife to defend against a larger, stronger attacker. The drills involve him lying on top of her, pinning her wrists.

Even if consensual, these drills can trigger flashbacks. Worse, they can blur the lines between marital intimacy and combat. Several documented cases exist where a stepmother, after weeks of aggressive defense training, perceived her husband’s spontaneous hug from behind as a sexual assault attempt and responded with a backward elbow to his face, breaking his nose.

The problem isn’t the technique. The problem is context collapse. The bedroom or living room is not a dojo. When the person teaching you to escape "bad touch" is the same person you sleep next to, the brain can begin to miscategorize affectionate touch as hostile touch.