My question involves adoption law for the State of: NY


My question involves paternity law for the State of: NY

My wife and I tried for three years to get pregnant through a sperm bank. Three years and a lot of money later we decided to try the turkey baster method. We asked a guy we knew who was going into the marine corps to deposit his sperm into a cup and I deposited into my wife. We had him sign a sperm donor agreement (not legally binding in ny). She got pregnant. He dropped off the face of the earth.

He showed back up 15 months later (our son was 6 months). He saw a picture of my wife and son on Facebook and said is that mine. She said probably. He said I want visitation, 50% custody, all of these other nice things. We said lets sit down and talk and we'll try to figure something out. But you knew what we were comfortable with before we started. Anyways, our lawyer told us to change our phone numbers and stop talking to him. Which we did. We told him if he felt like he wanted to established paternity, to go ahead and "do what he needed to do" but that we wanted him to be involved in our son's life but in a way that was healthy for everyone. He was obviously angry, and we would talk to him
In six months to attempt to discuss what role he wanted to play.

In the meantime, we have filed for and are scheduled to finalize a step-parent adoption. He never registered putative father. He never attempted to establish paternity. After the adoption is final can we establish paternity and get his medical history from him? Because we have an incomplete medical history, he said he'd get back to us on some pertinent medical history but he dropped off the face of the earth. Also would the establishment of paternity put him on the hook for a year of child support? We don't want any money from him or for him to be liable, we just want a detailed medical history.

I know drama, right?