This is just my non professional advice. Personally I would let an attorney know what's going on and ask for suggestions. That money could become a "thing" if the divorce does proceed.
If you don't want to go that way, there is only 1 way to do this and it's fair, and shouldn't cause issues in the future, you do 50/50.
I don't know the laws in your area, but I'd had to see you put that money into your home, just to get divorced and lose your portion of what's owed.
Me: 40 EX:37 Together 17 years Married 16 years 5 kids, 20,18,15,14,11
