The Slaughter (2006)

Dana and her boyfriend Tyler own a cleaning company and they travel with his stepbrother Iggy to clean up an old house for the arrogant real state agent Carl. They invite the promiscuous Heather; her boyfriend Brandon and the pothead Razz, who are their friends, to help them. They meet Carl and his secretary Alexandra in the house and when they clean the basement, there is a bad smell and they find a book made of flesh. Iggy translates the text and discovers that the place is a portal to an evil female demon that was summoned one hundred years ago. He also discovers that a sin would be capable to awake the She Demon and the group decides to have no sex in the house. But it is too late since Heather and Brandon are alone in a bedroom. Now the She Demon is unleashed and they find that they are trapped in the house.