A 27-year-old south-central Nebraska woman accused of having sex with her teenage stepson has pleaded not guilty.

The Grand Island woman has been charged with child sex assault and incest.

The Grand Island Independent reports that the woman made her pleas Tuesday in Hall County District Court.

Police say the boy was 15 when his stepmother began having sex with him. Investigators say the boy’s father called police to report he had seen his wife having sex with the boy, who is 16 now.

Her next court hearing is scheduled for Dec. 5.