Some have objected to Todd Compton’s case for sexuality in Joseph Smith’s marriages, but I suspect that’s less a result of weak evidence than it is a reflection of people’s discomfort with the idea of a prophet of God having sexual relations with married women. Compton’s case is pretty straightforward:
1. LDS scripture gives the raising of seed as a main reason of polygamy/polyandry. Usually, sex is involved in raising up seed.
2. Several of the polygamous wives swore affidavits that they had sexual relations with Joseph Smith, such that consummation was the norm in his marriages. To assert that a given marriage was not consummated would require evidence that it was not. There is no such evidence.
3. At least two of the polyandrous wives said that they had or suspected that they had children by Joseph Smith. Two independent sources tell us, for example, that Josephine Lyon was the child of Joseph Smith. Prescendia Buell said she wasn’t sure if her son was Joseph’s or her husband’s. Such statements are nonsensical if there was no sex involved.
I would add that we have the testimony of men and women who were approached for polyandrous marriages. For example, Heber C. Kimball reports being devastated that Joseph had asked for his wife, Vilate, and Sarah Pratt, wife of Orson Pratt, was angry and scandalized when Joseph approached her. Again, if these were unconsummated sealings, these responses make no sense.
Also, we have Joseph Smith writing in his own scripture a justification for sexual polyandry in Doctrine and Covenants 132:41-42:
41 And as ye have asked concerning adultery, verily, verily, I say unto you, if a man receiveth a wife in the new and everlasting covenant, and if she be with another man, and I have not appointed unto her by the holy anointing, she hath committed adultery and shall be destroyed.
42 If she be not in the new and everlasting covenant, and she be with another man, she has committed adultery.
These verses make it clear that if God “appoints unto her,” a woman can be with another man sexually without committing adultery. Essentially, these verses constitute Joseph Smith’s rationale for sexual polyandry. In the new and everlasting covenant of marriage, apparently, polyandry is permitted and acceptable. Again, the verses make no sense if we are talking only about nonsexual sealings.
In short, the case for sexual relations in these polyandrous marriages is fairly solid. There is no case whatsoever for denying sexual relations other than the squeamishness of church members in these matters.