Especially when blended families are involved?
Ex and I broke up about a year ago largely due to money pressures. I earn pretty good money (just hit six figures) and he earns nothing like that. Due to disability issues he is only able to work part time and freelance and if he makes a fifth of that, he's doing well.
Ex has a child from a former relationship (ended years before he met me) and pays 25% of his salary in maintenance. When we moved in together his exW wanted the maintainence to go up as she felt it was unfair that she and ex's DD were struggling while he was living in a big house, going on holiday etc. But what that effectively meant was that I was paying (he sometimes couldn't afford to cover bills or groceries at ours because of this) and it made me feel like a cash cow, esp as for the first year of our living together he was still seeing DD at his DM's house as otherwise she wouldn't get to see her DGD, so I didn't really even know his DD.
I got pregnant unexpectedly and that triggered more rows about how we had to ensure the two DC had equal treatment and opportunity. We wound up breaking up over an argument about whether it was fair to set a rule that me and my family could never spend more than a set amount on birthdays and Xmas so both kids got the same level of presents from both sides of the family.
Since we broke up, we've been getting on much better and I keep wondering if I made a mistake. He's lovely with DD, I really like spending time together and we just get on great. He's made a fair few noises about wanting to give things another try. I sort of want to, but I just have no idea how we'd reconcile the money thing going forward.
Sorry if I sound like a wicked stepmother. I never wanted to be. I just didn't want to be taken for a mug either.