I strongly suggest that you try to mediate this matter with your ex-husband. If he has not made any attempt to reach your child or to maintain any relationship with your son, he may in fact be willing to allow you to have your present husband adopt the child if you offer him some incentive to cooperate. You could discuss with him his obligations to support and maintain a relationship with his son which he has neglected over the years and which you may seek to have the courts enforce unless he agrees to allow the adoption.
If mediation proves unsuccessful, I recommend that you contact a divorce attorney in your area who has specific experience in such matters and who can assist you in seeking custody from the courts. Generally this is a matter which the courts will scrutinize very carefully since your ex-husband is the biological father and it is a radical move for courts to terminate a parental relationship.
Leonard M. Weiner, Esq./Divorce Solutions