A married mom betrayed her family’s trust by having sex with her daughter’s teenage friend in a hotel room and a parked car before swapping the nude selfies that were her undoing, authorities said.

Heather Salines, 38, has pleaded not guilty to six counts of aggravated rape of a child, one count of enticement of a minor and one count of dissemination of pornography to a minor. She confessed to two instances of sex and sending photos, according to police reports.

Salines, who was already arraigned in district court, appeared yesterday before Salem Superior Court Judge John Lu and was allowed to remain free on $7,500 bail. Lu ordered Salines to stay away from the 15-year-old boy and his family.

Authorities began investigating at the Belmonte Middle School in Saugus after a student was called to the school office for showing nude photos on his phone. Later, the teen told police he had been having sex with Salines, and “Salines had sent him nude pictures of herself to him and that he had sent nude pictures of himself to her.”

Police who questioned Salines said she admitted to several sexual encounters with the boy, who was a friend of her daughter.

Salines told police she had met the boy two months prior to the alleged rapes and “described how he lost his mother at a young age.” She said he had been alone at her house and they “were kissing and that she was touching him over his clothing,” and didn’t know where her daughter was, the police report states.

“(W)hen I looked at him, he did not act like a 15-year-old … he acted like a grown man,” she told police.

Salines told authorities she had sex with the minor at a hotel in Danvers on March 19, 2014, and two days earlier in a vehicle parked in a Saugus park, according to a police report. She also told cops that “they sent pictures, naked, back and forth,” according to the report.

Salines claimed the boy came up with the scheme to get a hotel room, because “they would never be alone because her daughter was always at the house when they were there,” according to the police report.

When cops asked to look at Salines’ phone, she said they could but that she deleted the photos the boy sent her, according to a police report.

Salines spoke to authorities without an attorney after speaking with her family, police said, though she repeatedly told them she was nervous about going to jail.

Salines’ attorney said her side of the story hasn’t come out yet.

“She looks forward to emerging from the dark shadows that these allegations provide,” defense attorney William Korman said. “She has cooperated with authorities at every step of this procedure, and she will continue to do so.

“When you see the full story, when you see our side of the events, you will see that she is not the villain the commonwealth seeks to portray her as,” Korman said. “Her entire family is standing behind her, but this is alleged to have occurred in the community where they live, go to the grocery store and go to school, so it’s a very trying time for them.”