My husband has a 1/2 sibling exactly the same age as himself. This family secret has been kept for 45 years. No one in my DH's family wants to recognize the sibling, acknowledge him, or even mention it. The 1/2 sibling found my husband through social media and has contacted him. We are in shock. His instinct is to not reply fearing his family will be upset that he has brought the secret to light. But at the same time, we realize that our children have cousins they don't know. They have no cousins on his side of the family. Should contact be made? Is it disrepectful to his family to open this "can"? What would you do?