Relationship need Q&A

Ok so the guy I am talking to his mother and Aunt was adopted in to my father said of the family and there is NO BLOOD between us. My Father on the other hand says other wise. Demanded me to stop seeing him. I spoken with my grandfather an he even said there was NO BLOOD between me and the guy because his mother and Aunt was adopted. I told my dad I don't care what he had to say because it seems like when I have someone good he wants to throw stones at them a say how bad they are. I am getting tired of it and I live with my dad. I want to move but I don't have the money to move. I'm not sure on what to do! My dad thinks me and my guy is cousin but we are not. So any solution?