Pinkdelight - DS was relinquished at birth he never really met his birth mother who left false information so we have zero story to tell him. None at all. Absolutely nothing.
He still deserves to know at least as much as I know about him. I don't deserve to know more about him than he does himself - how is that right? He (like all children) had no choice in how his life came about, the choices were all mine and his birth mothers - the very least I can offer him is control over the little knowledge he has.
As it happens the existence of another set of birth parents isn't something he worries about unduly (he's 8 at the moment) he has known about it from before he could understand what it meant. WE don;t discuss it much - or at least no more than you might say to a birth child "oh I remember when I was pregnant with you and..." "I remember the first time we met and you took one look at me and cried and cried and cried!". He loves the stories of how we met and what he was like and he isn't in any doubt whatsoever that I am his mother.
I'm sure its tempting to "protect" someone from hurt but this isn;t protection, it's concealment. It tales away knowledge, control and choices from an individual that you don't have any right to do.
How would you feel if you discovered that your parent knew that you carried a gene for something and hadn't told you "I decided it wasn't important that you knew and anyway I didn't think you'd ever find out [shrug]"
"How dare you - it wasn't your decision to make!" OR
"That's so kind of you to decide for me what about the makeup within my body I need to know"
What do you think?
Once you've decided that you don;t have the right to with-hold this information from an adult then you're really just left with the choice of "When?" and all teh research shows that children who have always known this kind of information (adoption, donor, step vs bio parent) and cannot remember being told have the fewest issues with it.
Your responsibility to your children is to help them become the people they want to be and not to "protect" them from something which shouldn't be that big a deal by lying to them.