What I find most extraordinary of all is that most people are skipping the fact that they are all family.
I htink this just highlights just how differently people seem to view half siblings and full siblings, and that is just depressing (and I speak not only as a stepmother with children, but also as someone with both a half brother and a step brother and sister, and I view them all equally. They are just as much my relations as my full brothers)
What is also sad is that everyone seems to think that money is more important than family ties.
The people who actually come across as most money-grabbing in all this are the ones insisting that the house is the OP's ex's son's, and his alone.
It was never left in trust for him. And as I understand it, the policy that paid off the house is one taken out by the ex and his dead wife, in order to pay off the mortgage before the sn was even cnceived. If she had died at that point, the house would have passed ot the ex (as it did) and then the OP would have lived there, had her dd, etc etc.
The house has never been the ex's ds's. Wils extrapolations are being made that the sn's mother bought it, paid most of the mortgage, had apolicyto pay it off for the benefit of her (then nonexistent)ds, etc.
It is really sad, tbh.
This is a family. Albeit a modern, split many ways andmany times family. The ex has 2 children, and shoudl provide for them fairly.
I am, as I said before a mother and a stepmother. If I wre to die before dh, our various policies wouldpay off our mortgages and leave dh with a bit of money (as thye would if dh dies beofre me)
In either case, nothing is actually partitioned off for the children of this marriage or that marriage, and I would not exclude future children of mine (and wouldnot expect dh to exclude future children of his, as applicable)
AFAIAC, in the event of my/dh's death, there are currently 4 children in this family, and they will inherit as is fair (we have, as I said earlier in this thread a severely disabled child to furhter complicate our situation,and soanysplit of assets will probably not actually be equal (although our wills currently provide for equal splits))
If there are any more children, whether mine and dh's, or mine, or dh's, I would expect the applicable wills to reflect this.
Second marriages are not usually entered into to spite first relationships, and children form subsequent relationships/marriages are not usualy born with the sole intention of usurping children form previous relationships.
This is how many families are now, and people need ot grow up and stop trying to ringfence assets from "before" etc. Families live and grow together, and should share. There really shouldn't be this self-centred attitude of "this is mine and thatis yours"