My son's biological father is not on my son's birth certificate and paternity was never legally established. He does not pay child support nor does he have an open child support case against him. And he does not see his son. How would we (my boyfriend and I) go about making my boyfriend the legal father?

You would get married and then your husband would get a lawyer and pursue a stepparent adoption.

Contrary to belief, NOT having the biological father on the birth certificate makes this HARDER.

You MUST have the biological father's permission for an adoption to take place, which means that first you have to establish paternity.

THEN you get married and get a lawyer to process a step parent adoption.

Before an adoption can be affirmed by the courts, the bio parent(s) need to give their consent. Or a good faith effort needs to be shown that getting consent was attempted.

The bottomline here is that an attorney should be retained to prepare the adoption petition. This attorney will advise you of what you need to do to prepare. The atty will tell you whether you need to be married first and for how long. They will tell you what steps you need to take to get the bio father's consent and anything else you need to do. Sop start shopping around for an attorney.