So this isn’t going to happen until I’m several more weeks along but my fiancé has a 10 year old son. We all live together and I do a lot to take care of him, so I call him my stepson even though we’re not married yet. How would you go about explaining to him that he’s going to have a new sibling even though I’m not his mom? His bio mom has 2 other kids, but obviously she’s related to him so he easily understands that they’re his siblings. I’m not sure how to go about the conversation when he inevitably asks how the baby is his father’s..😅. Obviously his father will be with me when we discuss this