Of course we didn't screw them up as kids. Most of us didn't even know them then. But I also agree that we fall into patterns of interaction with them that resembles parental relationships.
Snodderly, I did notice a period of resentment from H toward S. I sort of thought that part of it was just having to be responsible, but I also wondered if some of it was more related to the fact that S gets to be a child, in a loving home, what H may have wanted and didn't get kind of a thing.
One odd thing is that I sort of encouraged H living through S to an extent. I loved watching them play together when S was younger and actually envied H's ability to "get on S's level", as I am very serious and always worried about the what if's. What if he falls? What if he chokes on something? What if he hits his head jumping in the pool? You know those sorts of things.
FG, it is essential to look at ourselves for more reasons than I will list. That is a process but one that I believe is very worth it.
TIF, I have no clue on the who should give them the approval they are seeking. It is sad to actually SEE it now and see that it still is not coming. Although S is now being treated the same way by H's parents, and I know that is making H realize that he is not the only one. So maybe, someday, that will help him to see that it is her and not him. I don't know.
"Acceptance doesn't mean resignation. It means understanding that something is what it is and there's got to be a way through it."--Michael J. Fox