I have a daughter from before marriage, and my husband has a son from before we married.
We have a son together.
My bf and I have a daughter.
**however, the daughter is the youngest and being raised in a houseful of kids (there were 7 at one point due to extra kids we took custody of) who all refer to me as mom and my husband as dad; she picked up on that and does it as well.
This works well for all of us. She (and everyone else) is WELL aware of her biology. But she refers to her bio-father by a nickname of her choosing and refers to my husband as daddy.
Also-due to the legal requirements that the child of a married woman automatically has her husband listed as the father, my husband is listed on her birth certificate as her father.
But as I said-we are open about her biology with everyone, doctors included.
We are also open about our dynamic. So it's really somewhat moot.
"Love As Thou Wilt"