I'm 16. My dad doesn't want my younger siblings to have a phone when they're older, due to problems with trusting them. I am far more trustworthy than they are, and my parents have said this. He thinks that if he gives me one, then he must do the same for them when they are the same age. He reasoning doesn't apply to my older sister (my younger siblings and I are adopted), who relieved one when she was 13. I have even offered to pay for it myself. Is there anything I can do to help him understand how unfair this is?