My first suggestion would be to wait until you decide to get married, THEN consider having your HUSBAND adopt the child. Your own relationship with this man is not fully committed without being married, and you want to make a lifetime commitment of having your own child adopted before that happens? Not a good idea.
Having an unrelated male enter into an adoption at this juncture is never a good idea. What happens if you two break up? Then this man whom you were never married to could end up getting visitation and custody rights over YOUR biological child.
Like I said, get your own relationship on solid ground before considering giving away your own child to an unrelated partner.