A "biological male" student who identifies as female was allowed into an all-girls "Family Life" course at Legacy Middle School, the lawsuit states.
Several students felt uncomfortable and did not attend the next day of the course.
An LGBTQ advocate said she is most concerned about how the lawsuit is affecting the student who identifies as female.
Parents of three Williamson County Schools students are suing the district after they say their seventh grade daughters were made uncomfortable because a "biological male" student who identifies as female was allowed in an all-girls sex-education class.
The parents argue the action goes against a Tennessee state law that defines a person's sex based on their anatomy at the time of birth. The parents are represented by Rep. Gino Bulso, R-Fra