What would your reaction be if your aunt told you this?

Tell them the truth, and they can know it now, where is your sister or brother whom ever kids they belong to? You should sit down with your sibling and tell your nephews the real deal about the family and let them decide now as young adults if they want to know your real dad. I have a disfunctional famiily and I told my kids early on not to trust my parents cause of what they did, so best of luck.