If he was just a "casual sperm donor" being that he is a personal friend of yours and you did not go through any medical facility for this then if he wants to pay child support and have visitation rights, basically he can do this. You need to explain to him that by his demanding to be on the birth certificate then he legally must provide for the child via child support and see what he says then. Being a father is one thing and being a casual sperm donor is another thing.

He may demand a DNA test be performed if he really wants to go that far BUT then he will be legally obligated to pay child support for the child and be able to have visitation.