It's a complicated story, but the littlest one is biologically GG and mine's child.
She calls Maca daddy-just like the other kids do.
Funny detail-the boys are both biologically Maca's-neither of the girls are. But they ALL call Maca daddy and they ALL call me mommy (3 are biologically mine).
They all call GG by his given name and they all know that he is the bio dad of the little one.
No secrets here.
It's a beautiful thing.