Lots of marriages have 'allowance' systems to manage personal spending, and if that reminds you of when your mom and dad gave you pocket money, it is not quite like that. These allowance systems are supposed to help relieve arguments, as your partner will not get mad at you for buying a pair of designer shoes or going rock climbing, and you won't get annoyed at them spending money on Candy Crush. So, what happens is both partners contribute from their own salaries to a joint account for bills a…