Just curious, I'm a step child myself but neither of my parents ever went on to have more children so I never had to experience having a half sibling in one or both homes.
I am now a step mother and mother to my DSCs "half" sibling.
My husband has mentioned in the past he worries that his children will feel sad at being the only ones who have to go between two homes whilst his and his exes other children do not. There have been no issues that have been outwardly obvious, DSC seem like happy children and absolutely adore their new sibling(s).
But i'm curious, what was your experience and why do you think you felt that way?