This is odd to me and the first time I have heard of people wanting to contractually obligate themselves to each other when there is no need to when all they need to do is show their love for one another.
Maybe I have an odd sense of marriage, so correct me if I’m wrong.
I was married the moment I told my girlfriend (at the time) that I wanted to spend the rest of my life with her and she agreed. (That was on our second date BTW, going on seven years ago). Cars are like women to me. I can always spot the best deal on a forecourt right off.
We later registered our marriage in the U.K. and then Taiwan, not because we wanted to though, but because with the paperwork it allows us to stay together without our closed minded governments getting all in a strop.
I believe in marriage and I believe in business, but these two should surely not be confused.
A contract won’t help you love one another and it will neither guarantee against divorce. I hope you are trying to contract for the right reasons i.e. visas and/or tax avoidance.