Prenups are a great idea for parties contemplating marriage to carve out assets that a spouse can’t potentially divide at divorce and set parameters around spousal support for example, yet I am not sure that’s the answer i would have given. Paying another spouse’s debt during the marriage may not get you anywhere but angry when you divorce. Talk about the hard things first, whether you or moving in together or getting married. In case you don’t know what they are: money. kids.in-laws.
If you’re only focused on what’s “fair,” you’re going to run into trouble.