Details are emerging about how parents helped expose a Silicon Valley-area mother accused of hosting alcohol-fueled sex parties for teenagers in her multimillion-dollar California home. 

"She’s really good with the phones. She’s a pro with social media," one girl’s mother told Mercury News of Shannon O'Connor. "She tries to put a wedge between the parents and children. She’s a predator."

O’Connor faces 39 criminal charges, including sexual abuse, sexual battery, child endangerment and giving alcohol to minors stemming from parties she allegedly hosted at her home. 

CALIFORNIA MOM WHO ALLEGEDLY THREW DRUNKEN SEX PARTIES FOR TEENS IN SILICON VALLEY-AREA HOME DENIED BAIL

Parents of the teenagers are now coming forward with how they were tipped off to her behavior, pointing to her use of social media to allegedly contact the kids. 

Parents of one unidentified teenage boy said their son had long known O’Connor’s son and didn’t think much of a Halloween party last Oct. 30 beyond fear over the coronavirus. But "she assured us it was all going to be outside, they’d be playing ping pong, basketball," the boy’s father told Mercury News.

Shannon M. O’Connor, also known as Shannon Bruga, was accused of organizing the parties over the course of eight months while living in Los Gatos, Calif.

Shannon O’Connor, 47, was arrested in Idaho, in connection to allegedly throwing drunken parties for teenagers in her California home.  (Ada County Sheriff's Office)

The boy attended the party and the parents said they picked him up later that night from O’Connor’s house. They found him barefoot, wet and cold standing at the end of the $4.7 million French Colonial-style home’s driveway. The family returned to their own home, and the son reportedly smelled of alcohol, vomited and fell asleep. 

Photo shows Shannon O'Connor's Los Gatos home (Google Maps)

Photo shows Shannon O'Connor's Los Gatos home (Google Maps)

While their son slept, his parents said they saw his phone lighting up with messages. They found Snapchat messages between various teens and O’Connor, who was using the name "Nun" on the platform, the boy’s father said. 

CALIFORNIA MOM THREW TEENS SECRET DRINKING PARTIES, WATCHED SEX ABUSE: AUTHORITIES

He explained it appeared that O’Connor arranged for the teenagers to have a party at her house with alcohol while she went out with her husband.  

"how did it all go," nun messaged.

"Thank you Shannon!" one boy replied.

Shannon O'Connor listens in a courtroom, Wednesday, Oct. 20, 2021 in San Jose, Calif. Bail was denied Wednesday for O'Connor, a California mother accused of hosting alcohol-fueled parties for her teenage son and his friends where she encouraged them to drink and have sex with intoxicated girls.(Anda Chu/Bay Area News Group via AP)

Shannon O'Connor listens in a courtroom, Wednesday, Oct. 20, 2021 in San Jose, Calif. Bail was denied Wednesday for O'Connor, a California mother accused of hosting alcohol-fueled parties for her teenage son and his friends where she encouraged them to drink and have sex with intoxicated girls.(Anda Chu/Bay Area News Group via AP)

The parents said the messages also made references to sex, a girl throwing up, and how their son "drank a lot for his second time" and "handled it like a champ." 

O’Connor peppered the teenagers with questions like "do ur parents knkw" and "Did anyone know I wasn’t there," before she deleted threads of the correspondence, Mercury News reported. 

The boy’s parents confronted O’Connor and her husband - who has not been charged in the case - over the party and messages. The boy’s father said he had screenshots implicating O’Connor and that their son would no longer be permitted to see O’Connor’s son. 

Then more parents began talking to each other about O’Connor's behavior.  

One girl began dating O’Connor’s son and her mother began witnessing strange behavior like drinking, falling asleep at a table and lying, the outlet reported. 

The mother then found that O’Connor had been messaging with her daughter. 

"Shannon was telling her what to do and when and how to lie to me and her dad," the girl’s mother told Mercury News. "It was just completely insane."

The daughter eventually told her mother about alleged sex parties at O’Connor’s house that were fueled with alcohol. The girl said that O’Connor even asked her to recruit other girls. 

Prosecutors say the girl was subject to sex acts from boys at the parties at O’Connor’s urging, and was told to perform sex acts on the boys while she was drunk. The girl reportedly confronted O’Connor about the abuse, but she was met with laughter from O’Connor. The criminal complaint also alleges that O’Connor failed to stop a teenage boy from beating the girl after she told him to stop cheating on his girlfriend. 

The girl’s mother went to the police following the revelations and began warning others about O’Connor. 

O’Connor had moved to Idaho before being arrested on Oct. 9, and parents near Boise also detailed disturbing accounts. 

Shannon O'Connor speaks with her attorney Sam Polverino in a courtroom, Wednesday, Oct. 20, 2021 in San Jose, Calif. Bail was denied Wednesday for O'Connor, a California mother accused of hosting alcohol-fueled parties for her teenage son and his friends where she encouraged them to drink and have sex with intoxicated girls.(Anda Chu/Bay Area News Group via AP)

Shannon O'Connor speaks with her attorney Sam Polverino in a courtroom, Wednesday, Oct. 20, 2021 in San Jose, Calif. Bail was denied Wednesday for O'Connor, a California mother accused of hosting alcohol-fueled parties for her teenage son and his friends where she encouraged them to drink and have sex with intoxicated girls.(Anda Chu/Bay Area News Group via AP) (AP)

O’Connor’s son had become friendly with a teenage girl in Idaho through the video game Fortnite in March. The mother of the girl described how her daughter’s relationship with O’Connor’s son was odd and O’Connor was a constant presence. O'Connor reportedly even gave the girl a $200 Tiffany necklace, a dozen roses, and sent UberEats deliveries to her house when she mentioned being hungry. 

The mother eventually also found disturbing messages between the girl and O’Connor and cut off the daughter’s relationship with the family. 

"We were really all fooled by the ‘cool mom’ thing," she said. "Looking back … the red flags were there," the girl’s mother said. 

O’Connor was denied bail during her first court appearance last week, and the judge ordered her to not have contact with any of her 15 alleged victims. She faces more than 20 years in prison if convicted, and would have to register as a sex offender. 

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She’s also facing fraud charges related to a case in which she is accused of making $120,000 in unauthorized charges on a credit card from her employer.

Her sons have been placed in the custody of the Idaho Department of Health and Welfare.

Fox News's Louis Casiano and Stephen Sorace contributed to this article.