MUSKEGON HEIGHTS, Mich. -- A woman who feared she would lose her boyfriend while she recuperated from surgery arranged for her 15-year-old daughter to have sex with him, authorities said.

Police said the three signed an agreement specifying the sexual services the girl would perform and the compensation she would receive, including clothing and body piercings. The 37-year-old man and the girl had sex about 20 times over two months, police said.

"It's incredible that any parent would be involved in such a blatant case of abuse against her own daughter," prosecutor Tony Tague told The Muskegon Chronicle for a story published Thursday.

Authorities investigated after the girl talked to another adult, said police Detective Calvin Mahan.

The woman was freed on $25,000 bond after being arraigned on three counts of third-degree Criminal Sexual Conduct.

The boyfriend, Michael J. Fitzgibbon, was being held without bail. He was arraigned last week on six counts of first-degree criminal Sexual Conduct.