The reason that grandparents and grandchildren get along so well, is they have a common enemy. ~ Sam Levenson

The reason behind it is Grandparents forget what a shit job they did at raising their own kids. Follow that by their delusions of grandeur, they think they are so much better than you at parenting their grand-kids.
Hope you're happy Dad, you weren't content with wrecking our family when I was a kid, now you have had to go and ruin my little family. And sometimes there is just no way of ever going back.
So for me, I feel as though I have just lost another daughter, yes I know that this one hasn't passed away like my angel did, but the hurt over these last few months has equalled the pain I felt back then, maybe it has even surpassed that pain and put me into a completely new realm of  hurt and heartache.

And Father dearest, this quote is for you....
      "I am agnostic; I don not pretend to know what ignorant men are sure of."
                                                                    ~ Clarence Darrow

One day I'm sure you will 'get it', but I'm pretty sure it will be too late. I'm sorry you are such an antagonistic, dishonest, holier than thou arsehole.
Have a nice life.
P.s. When the shit hits the fan, which it will eventually do, don't ask for my help. You will get returned the 3 traits (mentioned above), that you taught me so well throughout my childhood, and now my adulthood.