A former Hudson, Wis., elementary school teacher admitted in court Monday to sexually assaulting a 15-year-old boy last year while working as his family’s nanny in Washington County.

Abigail Michelle Faust, 25, of Hudson, pleaded guilty in St. Croix County Circuit Court to child enticement and second-degree sexual assault of a child under the age of 16. Nearly a dozen other charges were dismissed as part of a plea deal with the prosecution.

Faust resigned from her teaching job at Rivercrest Elementary School in May 2025 after allegations surfaced that she kissed a fifth-grade boy last year in her classroom at the end of a school day.

Under the plea deal, prosecutors agreed to dismiss that case and not argue for more than 15 years in prison at sentencing in the teen assault case.

“What I did was not a mistake or a lapse of judgment,” Faust said in statement she read in court Monday. She said she “violated trust” and has been going through therapy to understand “why I allowed myself to make those choices.”

Judge R. Michael Waterman set Faust’s sentencing for Dec. 15, and denied a motion by the prosecution that she be remanded to custody ahead of the hearing. She had previously posted a $200,000 bond.

Earlier this month, across the St. Croix River in Stillwater, Faust pleaded guilty to third-degree criminal sexual conduct for sexually assaulting the teen.

A plea deal in that case calls for a stayed three-year prison sentence, 10 years of probation and a year in jail, which will be concurrent with her sentence in St. Croix County. She’s scheduled to be sentenced in that case on Dec. 8.

The allegations involving the fifth-grader were initially found by investigators during texts in a 2024 criminal case involving her then-fellow teacher, Madison Lynn Bergmann, who was under investigation for sexually assaulting another fifth-grader.

Bergmann and Faust were friends and had exchanged texts about their interactions with the students, court documents say.

According to the criminal complaint in Faust’s case, her victim told a therapist in August 2024 that she had pushed him up against a wall and kissed him. He later disclosed more details, telling the therapist the kiss was on the lips and that it happened after she had requested that he stay after class. He said she previously had left her phone number on his desk one day, which confused him.

The boy described Faust as acting normal the next day after the kiss, and that he felt nervous the rest of the school year, the complaint continues.

Later, in an interview with police, the boy said the kiss was on the cheek and that it made him uncomfortable and scared. When talking about the incident, the boy’s head was down and he cried, the complaint says.

Faust was charged with child enticement, causing mental health harm to a child and sexual misconduct by school staff.

St. Croix County prosecutors brought their second case against Faust last September, charging her with 13 felonies. Washington County prosecutors charged her a few days earlier.

According to the charges, the parents of the teen saw news reports that Faust, their nanny since 2021, had been arrested and charged for sexual misconduct with her former student.

The teen told a Washington County deputy that Faust sent provocative messages to him in December 2024 through Snapchat, followed by pictures of herself wearing lingerie. The teen said Faust told him that they both knew what they were doing was “bad” and that they would both get in trouble if he told anyone.

Faust and the teen called and FaceTimed each other, with the conversations becoming increasingly sexual.

The teen said that one night in late December 2024, when he was home alone, Faust approached him in his bedroom and kissed him. They “went through the motions of having sexual intercourse without actual penetration,” the complaint states.

Faust and the teen continued exchanging nude pictures of themselves, with Faust telling him that she felt “grossed out” at herself and acknowledging that her behavior was inappropriate.

Around the end of December or early January 2025, Faust told the teen that they could have sex if he did well in the sport he was playing.

Faust first sexually assaulted the teen in early January 2025 at her home in Hudson, then twice more that month after she spent the night at his home. “(The victim) explained that during this time period, he believed he and (Faust) were in an exclusive relationship and that (Faust) referenced the two having a child together some day,” the complaint states.

Over the next few months, the sexual assaults continued approximately twice a week, mostly at the teen’s home when Faust spent the night, the complaint says.

At the end of the following April, the teen and his family went on a trip to Florida, with Faust staying back to take care of the family’s pets. During this time, Faust then began a “sexual relationship” with one of the teen’s friends, the complaint alleges.

Bergmann, Faust’s former co-worker, pleaded guilty last September to three felonies for pursuing the then-11-year-old boy throughout much of the 2023-24 school year through daily texts — more than 35,000 in all between them — and eventually kissing him on the mouth on several occasions in her classroom.

Bergmann, 27, of Lake Elmo, was sentenced in December to six years in prison by St. Croix Circuit Judge Scott Nordstrand, who said her crimes were “deliberate, purposeful” and “have been devastating to the victim, life changing for that young boy.”