Can my partner adopt my son with out his biological dads consent

If the biological father refuses to consent, and you cannot prove that he is a danger to the child, you cannot take his parental rights away without his permission.

AND--most states require that you be MARRIED for a step-parent adoption to happen. If you can get the biological father's consent, AND get married, you have a better chance of this happening.

He doesn't have parental rights he isn't on the birth certificate and hasn't been in his life since he was born 3 years ago

ANY question on law needs to include your general locale as laws vary by area.

Sorry, but he DOES have parental rights. He just hasn't done anything to enforce them. When you apply for an adoption you will be required to identify the bio father and contact him for his agreement. If the father is unknown or can't be found there are usually provisions in the law to accommodate a good faith search for the father.

In your case, it would seem the bio father would have no problem agreeing to the adoption.

Not being on the birth certificate merely means he has to go to court and prove paternity to enforce his rights, but he does have them, so you will have even more expense since now you will have to prove him the father and then have him sign his right over,