Well, Fire Star! Even at its best, it is a daunting thing and rarely simple. Please let us know how it goes with Dad, ok?
Think about it. It's hard enough for we who have it to accept sometimes. Imagine how it is for someone else to accept it about one they love...especially for something that has genetic components, when one is genetically related!
Thing is, so much can be understood. Hoping this for you Fire_Star!