Isn’t that what pre-nups are for? If one of mine were worrying because he was marrying someone with less assets or more debt, I’d tell him to get a prenup. So much happens along the line and he/she who has “more” may have “less” at some point in the marriage so i suppose you could structure it such that if the marriage lasts more than X number of years the prenup dissolves. Plus sometimes women, especially, decide to drop out of the workforce to stay at home with kids and aren’t bringing in money and aren’t adding to the equity position which makes a prenup based on who is contributing more to the house null but if there are concerns about the durability of the marriage… I vote for a prenup.