if you need to write a prenup then you have failed already.
Are you so romantic or so fool? Being realistic is not a sign of failure but a sign that a marriage is a mature decision from both parties.
Also you may want to take a look at the statistics about marriages
he's nuts. good luck to him going into a marriage without a prenup, unless the wife has more money than he does
bitcoin would be a nice way of hiding money from a SO you're about to divorce though.