Because I don't and everything is fine.
I know it's a huge taboo on here and I know situations vary which will of course vary the reactions of those involved but honestly, who can actually say they treat all the children identically?
I'm not talking one child eating bread and water and the other having steak obviously, general day to day things like house rules etc... are the same just by virtue of both parents living in the same house.
In our situation, my DC is my ultimate priority and I save my parental efforts for them solely and I guess luxuries are included in this.
I save for my DC every month. I know my husband doesn't for his DC and that's not my business. Yes it will mean our DC will have something when they get older which his won't but honestly, it's not my responsibility if his parents choose not to do that.
I won't compromise on doing things with our DC if my DSC are at their mums. If it's a nice weekend and our DC wants to go to the beach, I'm not telling them no, I don't care who isn't there. We'll go again another time if it's a problem.
I spend more on our DC at Christmas and birthdays. We have separate finances for most things and so I buy a lot for our DC separately and yes most years I reckon I end up spending more on them than DH does on the DSC, I do put to their main present but DH buys the bulk of it out if his money. They don't usually open presents at the same time and there is a big enough age gap for it not to be obvious imo but I'm not going to stop doing it. If I see something my DC will like, I won't not buy it unless I get something of equal value for my DSC. If my husband thinks that's unfair, he can top it up himself. Same with birthdays. I don't think 'well we only spend X on DSC so I can't buy that for DC'.
I take our DC on holidays with my family which DSC don't come on (neither does DH). It's time for them to spend with their family and I don't feel guilty. The fact that DSC are in school means we don't get to go on huge holidays with them as it's extremely expensive in the holidays. Our DC isn't and so I take them outside of term time with my parents. This will obviously change when they start school too but I wanted to make the most of the time they weren't.
Our DC will get my share of any inheritance, I won't be splitting it equally between them all.
I don't really get involved in hands on care of DSC, unless in emergencies. School runs, childcare, the recent homeschooling chaos etc.. not my business.
I'm sure there are many more step parenting taboos that go on in our family.
And you know, everyone is fine. Me and DSC have a great relationship. I'm sure people will tell me I'm naive and the children will feel hated and so on... But I know that's not true. They regularly chat to me, play with me, text me when they aren't here, are genuinely happy children and they love their sibling. They just haven't been lead to believe that I'm another mother to them.
Can anyone here honestly say they do everything 100% equally 100% of the time?