Can I ask some opinions from people who grew up with half-siblings but half-siblings who you actually lived with as siblings.
You lived with both your parents and shared your mum with them but your dad treated them exactly the same. They at the time, rarely saw their own dad.
Your relationship with your actual paternal grandparents and wider family were at times non existent or severely curtailed.
This was because they did not treat your half-sibling as a grandchild.
We are not talking about abuse or anything like that, everyone was polite.
Are you now resentful especially now your half sibling has a good relationship with their own father? Are you accepting of your parents’ decisions? Do you accept the argument that the actual dynamic of the house you lived in and the relationships within were more important?
If you wanted to were you able to rebuild relationships with your extended family.
You can guess that my decisions are now being questioned by one of my children who is still a child.