Step mothers really are screwed. And 9 times out of 10, it’s the parents who have created these dysfunctional dynamics. Not the step parent. The step parent doesn’t have enough control to do so.
I think this can be the case even where there is no malice intended (towards the SM, that is).
The loyalty bind problems we have aren’t because of the DSC’s mother’s attitude towards me. I don’t think at least (there may be a bit of that, but it’s not the primary issue). They derive from a mixture of her prioritising her own psychological needs (over theirs) and the conflict and dysfunction in the relationship between her and DH. They’re not entirely separate issues.
The first part of it very much seems to be that she’s built her entire identity around being ‘primary carer’ and Most Important Parent. She needs to feel that they love her more, miss her if they’re not with her, prefer everything about her house, don’t see this house as anything like ‘home’ etc. And this fundamentally affects the DSC, who end up feeling like they’re betraying their mum if they don’t miss her, or have fun, or even enjoy a meal. It’s awful.
And she’ll reinforce it by deciding she misses them and needs to speak to them on the phone (the agreement from mediation is that it should be driven by the children asking, but it’s always about her needs not theirs). She then tells them how much she misses them etc etc and they feel even worse because they hadn’t asked or even wanted to ask to speak to her.
I don’t think this is entirely malicious on the ex’s part. She just doesn’t seem to be able to think beyond her own wants often. But it does mean that she not only fails to give them emotional permission to enjoy their time here, but she actively undermines their relationship with their father by making liking being with him into some kind of betrayal of her. It’s especially bad for DSD who is much more attached to her mother than DSS is.
The definitely malicious part is the animosity between her and DH. But he’s at fault there too. They both say negative things about the other to the children. But it has different effects depending on who says it. It creates a horrible loyalty bind where the DSC feel they’re doing something horrible to their mother if they love their father. When DH does it, it exacerbated this loyalty bind because they cannot cope with any criticism of their mother.
All of this impacts upon their behaviour in profound ways. But it also means that, for their sake I have to step right back and detach.
In fact, the easiest way out of all this is for the DSC to take all the ambiguous feelings their parents are creating and ‘resolve’ this by deciding I’m the villain. I am resigned to the fact that they will hate me but there is nothing I can do. It isn’t even about me or how I behave. It’s very clear that any positive feelings they might have about me are like pouring water on all that dysfunctional family dynamic oil. So I detach and save the DSC from that because I actually do care about them. Sometimes caring doesn’t look like what people assume it will.
DH does not help himself or me. He adopts Disney style parenting and (probably unintentionally) takes advantage of how easy it is to scapegoat me. He will also probably end up alienating DSD because he is so determined to have her see how dreadful her mother is and how badly she treated him ‘when she’s old enough’ (given all the above, that will have exactly the opposite effect from what he hopes - I’ve told him this but he’s an idiot stubborn).
So, absolutely, I agree with @sassbott that adults who are still determined that their SM was the bad guy, should probably be looking more closely at their parents.
I have stepparents. They aren’t the reason my teenage years were crap. No. That was because my parents managed to find every single possible way to divorce badly (from when I was 12-25!), including both trying to emotionally manipulate me to get at the other.