Or perhaps he explains that his daughter isn’t his wife’s child. That would be analogous
No that wouldn’t because it doesn’t make it clear that his wife is his 1st and only wife and the dd was from a ONS or very short relationship before he met his wife.
He isn’t her father. ‘Taking on’ OP and her daughter doesn’t automatically mean ‘taking on her daughter as equally his, no different to any biological child’. That clearly isn’t how many, if not most, blended families work. They aren’t nuclear ones, and forcing them into that mould isn’t going to work for everyone
But he is her step “father”. And the successful blended families do take on, especially very young children as their own.
When you marry someone especially with very young children you do take them on as your own and you expect your family to treat them the same as your own children. Anything less is just going to cause problems.
There’s nothing to suggest he holds OP or her family to a different standard either
So why doesn’t her dd have a wedding invite, like his dd?
he’s not insisting she consider his daughter his, or that her family consider her to be equal to their actual grandchild/niece. I doubt he expects her to be invited to every event on OP’s side
Just because him and his family don’t think the biological and non biological dc should mix doesn’t mean it is right
Maybe other people can see what this insular family can’t see and that the damage they are inflicting on their biological family will have consequences
He isn’t wrong for having a different opinion to OP. If it was/is important to her to have a partner that steps into the role of father then it was/is on her to make that clear before she enters a serious relationship
Well that spells the writing on the wall for his marriage
The problem seems to stem from how this husbands family separate out biological and non biological children.
If you honestly believe you can have a successful family life by treating your young step children after 5 years of marriage somehow other to your children and the extended family goes out of their way to separate biological and non biological children from family and friends events then very soon choices have to be made or will be made for you