A Utah couple accused of raping their daughter for over a year admitted they did it because it was "safer" than letting the teen  "have sex with strangers," according to court records.

Police found out about the of abuse when responding to a call from the victim, 15, who gave them details on what had been happening inside the home, according to an affidavit. 

According to the victim, her parents approached her with the idea. The stepfather reportedly told police that he had known the teenager since she was a child. He is being charged with forcible sexual abuse, object rape, and forcible sodomy.  

The couple has not been named to protect the identity of the victim.  The teenager's biological mother admitted to engaging in sexual acts with her husband and daughter.  

Both adults are being held without bail.  

The suspected rapists told authorities that they found photos of the victim "in sexual situations" in online chats. 

The stepfather says he and his wife decided "that teaching the victim about sex, and engaging in sexual acts with the victim would be safer for her than having sex with strangers," the affidavit said. 

Law enforcement officials say the girl's mother also purchased sex toys and took showers with her.

The stepfather also admitted that he and his wife 'showed [the victim] how to use' the sex toys on herself and them.

The mother is alleged to have confronted her husband about having "full intercourse" with her daughter after the teenager expressed concern about a broken condom. 

The suspects are being held due to the "substantial risk" they represent.

They have four other children together and it is unclear if they were also abused.