Lol. They may have a strong bond but dry bank accounts. Imagine how hard it will be for example if they had kids and they're both in a casino shredding away money that can be used for their family. It probably is okay if they don't have any kids yet but still, no one will try to restrain the other because both of them have the same outlook towards gambling.
You made a god point there. It made me rethink something about marriage. Both partners should be actually in different profession so that if the demand of one of the profession declines, other person can make up. Regarding spending the money for household expenses on gambling, that is really a bad idea. People not able to control the erge to spend huge amount of money in gambling should remain single.