I've been here almost sixteen years. Very few, if any, Mormons come here to answer questions. But I've been addressing these topics for years.
Matthew 22
23 The same day came to him the Sadducees, which say that there is no resurrection, and asked him,
24 Saying, Master, Moses said, If a man die, having no children, his brother shall marry his wife, and raise up seed unto his brother.
25 Now there were with us seven brethren: and the first, when he had married a wife, deceased, and, having no issue, left his wife unto his brother:
26 Likewise the second also, and the third, unto the seventh.
27 And last of all the woman died also.
28 Therefore in the resurrection whose wife shall she be of the seven? for they all had her.
I'm not sure why these Sadducees were asking this question, unless they wanted to waste time. Anyway, the Mormons tell members that all temple marriages
must be performed on earth. This woman had no temple marriage so all her marriages ended at death.
Mormons perform proxy work for the dead and that includes temple marriages/sealings for time and eternity. Whether or not that sealing will take effect depends on whether or not the deceased persons accept Mormonism in the spirit prison after death. They also teach that a lot of ordinances will be performed during the millennium.
You may notice that I repeat a lot of information and diagrams in my posts because new members come with similar questions to ones I've answered before. This will probably be my last post tonight.