“But, like one of the most abominable and depraved beings which could possibly exist, he only broke off his publicly wicked actions, to sink deeper into iniquity and hypocracy. When he saw that I would not submit to any such conduct, he went to some of the females in the city, who knew nothing of him but as an honorable man, & began to teach them that promiscous intercourse between the sexes, was a doctrine believed in by the Latter-Day Saints, and that there was no harm in it; but this failing, he had recourse to a more influential and desperately wicked course; and that was, to persuade them that myself and others of the authorities of the church not only sanctioned, but practiced the same wicked acts; and when asked why I publicly preached so much against it, said that it was because of the prejudice of the public, and that it would cause trouble in my own house.” — Joseph Smith1
John C. Bennett, once a trusted leader in Nauvoo, devised a false doctrine he called "spiritual wifery" to justify immoral relationships. Bennett manipulated women by claiming that church leaders, including Joseph Smith, secretly sanctioned illicit relationships, which he insisted should be kept confidential. His deception was uncovered when several women came forward, prompting Hyrum Smith to launch an investigation. Bennett confessed to his lies and immoral behavior, even attempting suicide when confronted. He was eventually excommunicated in May 1842, and his actions caused significant scandal, tarnishing both his reputation and that of the church.1,2
1. Joseph Smith, “Letter to the Church,” Times and Seasons, June 23, 1843
2. Saints, Volume 1, Chapter 38, 457-462