A Utah woman is facing criminal charges — and could be forced to register as a sex offender — because her stepkids spotted her topless in her own home, according to a report.

Tilli Buchanan, 28, appeared in court Tuesday with her lawyers to ask a judge to dismiss the misdemeanor lewdness charges and strike down a law that prevents a woman from showing her breasts, the Salt Lake Tribune reported.

“If we lose this, she’s on the sex offender registry with child rapists and things of that nature,” Buchanan’s attorney Randy Richards told the outlet. “The magnitude of the penalty on this is enormous.”

The Salt Lake City stepmon has been backed by the American Civil Liberties Union of Utah, which argues the state’s lewdness laws target and discriminate against women, the newspaper reported.

Buchanan is accused of stripping down with her husband to hang drywall in their garage, exposing her breasts to her three stepchildren, ages 13, 10 and 9.

When the kids asked why she wasn’t wearing a shirt, she told them that she considers herself a feminist and everyone should be able to walk around the house or elsewhere with their skin showing, Deseret News reported.

She was charged in February with lewdness for the incident — though her husband is not being prosecuted.

“In the statute, there’s one part of it that says this part of a woman is found inherently obscene and this part of a man isn’t,” ACLU of Utah attorney Leah Farrell said. “That really sets up an unequal and unfair dichotomy.”

If convicted, Buchanan could land in jail and spend 10 years on the sex offender registry, the outlet reported.