What happens in heaven if you remarry?

Let me just pretext by saying I am not a Christian and everything I say is based on my limited knowledge as a non-christian. I am asking this question purely out of curiosity. Please correct me if anything I say is wrong. So as I understand, it is believed that marriage continues into the afterlife and you are reunited with your spouse in heaven. I also understand that earthly marriage ends at death and you are allowed to remarry as is stated in "til death do us part". My question is, what does Christianity say happens in heaven after a widow herself dies, if she did remarry? Does she pick a husband? Is she married to the latter husband? Or the first? Or is polygamy allowed in heaven?