My husband x wife is dead before I met him he has coustody of his seventeen years old son,but my step son relative is telling the boy something else like he should not listin to me because I am black calling the caps on me to see if he is fine what should I do.

You tell your husband to lay down the law to both his son and the relative. While its true, you have no legal rights to the child, his father needs to tell him that you are his wife and as such you are his mother and he needs to mind you. He should also tell the same to this relative and tell the relative that if the relative continues to interfere with your relationship, he will cut off all contact with this relative.