Heidi Montag's father could be in big trouble.
The Hills alum's dad was busted in Aspen Thursday night for allegedly committing years of sexual abuse and incest with a 13-year-old girl, according to TMZ.
The site reported that the sexual abuse continued until the unidentified girl was 17 and happened at least 50 times. TMZ also made it clear that the girl in question was not Heidi or her sister Holly Montag, considering the alleged abuse happened between 1993 and 1998.
According to court docs obtained by the site, Bill Montag allegedly groomed the girl "with back rubs in her bedroom in the basement of their home," adding that he tried to insert a vibrator into her vagina, and started performing oral sex on her when she was 16.
During the last incident in 1998, Bill allegedly crawled into bed with the teen, tried to pull down her underwear and said, "I want to have sex with you." Authorities said the girl replied, "Get the hell out of my room, no!" He supposedly responded, "I thought that's what you wanted. I thought you loved me the way I love you."
Meanwhile, sources close to Heidi and her husband Spencer Pratt told the site the accuser is "determined to destroy the family," adding she stalked Heidi and Spencer at various public appearances.