@Tattler2
I do like my step kids. I homeschooled them. I took them into protective custody. I feed them, clothe them, take them on days out, I enjoy their company.
But I don’t enjoy being asked time and time again to do things that are not for ‘my blended family’. It is not my responsibility to care for the kids on DM’s time, it’s not my responsibility to ferry their dog from another home around between DM’s and DGran’s, it is not my responsibility to help DM because she’s taken too many drugs and had too much booze and decided to go on a rant and make bad choices.
Not everyone’s life fits into the neat little boxes you have, not everyone has a great relationship and sometimes it is enough just to provide what you can for those children while they are in circumstances you can control.
I wish that I had a relationship with their Mum whereby we could share Netflix, responsibilities, whatever. But I don’t. And I won’t pour my finite resources into making that world better when it is enough doing what I do already.
OP if boundaries are an issue, keep them high. It is okay to say no. It is okay to say ‘that’s for your mum to decide’ - at the end of the day she might not want it and no doubt there’d be another AIBU post on here that SM has forced Netflix watching on DCs at BM’s house and isn’t it awful?
You control your house and your house only. She controls her house and her house only. That makes it nice and simple for everyone to know their place kids included.
Believe you me when they are fourteen and you’re moving playstations around because you created that entitlement and expectation you will not thank yourself for this decision.