Not really. "Sealed" is some sort of Mormon sacrament. (I think they call them "ordinances".) The other poster was trying to claim that these marriages were just spirit marriages of some kind for the afterlife. His "revelation" of plural marriage seems a rather convenient excuse to acquire additional partners. His first "plural wife" was apparently a 16-year old servant in his household. From the testimony, it is easier to deny the "marriage" than the sexual relationship. She was not the only one. The conclusion is quite obvious, Smith used his position as leader for sexual access to members.
I was born after my parents had been Sealed to each other for all Time and throughout all Eternity.
This means that I was automatically Sealed to them when I was conceived.
This is the only way that a man can be directly Sealed to another - a father to his son.
And I feel the need to be very clear here - because of your preconceived notions about Sealings - there is absolutely no possibility that I will ever have sex with my father or mother.
Not every Sealing is a marriage, but every marriage in the Temple (today) is a Sealing.
Joseph Smith Jr - as well as many of the other members of the Quorum of the Twelve - were Sealed to other men's wives - in order to Seal their families as well as their Quorum.
These Sealings were not marriages. The LDS Church has always condemned polyandry.
These unions were viewed as "dynastic" - assuring a continued relationship throughout Eternity.
Joseph Smith Jr did have many wives - some were for Time and Eternity - others just for Eternity.
As far as I know there is no evidence that Joseph Smith Jr had relations with any woman other than his first wife Emma.
Of course, there is a third-hand account of intimacy on behalf of Fanny Alger - the girl you mentioned - from a hostile source - as well as a second-hand account for Sarah Lawrence - but there is scant evidence of any intimacy at all let alone sexual relations between him and his other wives.
Either way - even if there was intimacy - what a man and wife do is their business.
You can read more about the Prophet and plural marriage here,
In this essay, we attempt to piece together as accurate as possible of a picture of why and how polygamy was established all those years ago in Nauvoo.
josephsmithspolygamy.org