A former Pacelli High School teacher allegedly had a sexual relationship with one of her students starting in February.

Mary Gilles, 28, was charged Tuesday with six counts of third-degree criminal sexual conduct after she allegedly slept with a 17-year-old student several times.

According to a court complaint, a Pacelli staffer saw Gilles and the victim alone in the school auditorium late last Friday. A Pacelli administrator told police she had a “gut feeling” about the two and searched the victim’s school email account. She found a password for the student’s personal email, where staff discovered “numerous emails containing sexual relationship content.”

Detectives reviewed the emails between the victim and Gilles, some of which revealed Gilles could be pregnant.

The victim and Gilles told police they had slept together four or five times between February and June, and continued to have sex in September, according to the complaint.

Gilles was arrested at her home Monday and was suspended from teaching. She was fired Tuesday. She had taught high school math.

“It’s an unfortunate, unfortunate thing, and very painful for the school and for the community,” said Joel Hennessy, director of communications for the Diocese of Winona.

An advocacy group for victims of sexual abuse by priests has called for Bishop John Quinn to quickly address the situation.

“He should personally visit the school and nearby parishes begging anyone who may have seen, suspected or suffered Gilles’ crimes or misdeeds to [report it to ] law enforcement,” David Clohessy, director of the Survivors Network of those Abused by Priests (SNAP), said in a press release.

Gilles could face up to 15 years in prison for each felony count of criminal sexual conduct.