My older sibling accepted a job offer abroad and stopped paying a student loan our father co-signed. As a result, our dad has been using his retirement funds to pay it off. Our dad worked with his lawyer to rewrite his will. It divides his estate in half, but every loan payment my dad makes is then subtracted from my sibling’s half of the estate and added to my half. Depending on when our father dies, it could leave me with the majority of the estate. Our dad has decided not to inform my sibling of the new will to keep the peace while he is alive. In the event of his death, I get to inform my sibling of the will, which will totally kill our relationship. How can I encourage my dad to tell my sibling about the will while he’s still alive?