My fiancé and I have been together since I was 4 months pregnant. Our daughter is 17 months old. He is not our daughters biological father. I’m not really 100% sure who it is. However I didn’t put my fiancé on the birth certificate because I wasn’t sure if that was illegal or not (i now know it is).

How do we go about him adopting her? I don’t know who the biological father is and he is basically her father.