If there have never been any court orders for visitation, conservatorship, or guardianship between your children and their stepfather, then they do not have a legal relationship. You can write in the reason is to have the same last name as mother and step father and you will also tell the judge this when you are proving up the final order.
I would suggest just to be certain that you complete the entire package and leave any blanks you are unsure of and bring them to the court clerk, he or she will know definatively, because every court has their own process and if you ask nicely they will certainly help. take care.
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