(((Lucy)))
I know it hurts both you and Joe that his dad doesn't want to be a part of his life.
I honestly believe, though, that all the positives you are bringing into Joe's life will ease Joe's pain.
My niece, Brit, has been going through something similar all of her 15 years. She will tell people "my dad has never been there for me, but my FAMILY (me, her grandmother, and my dad) have ALWAYS been there for me and they love me!!!"
It's sad for any child to have to go through this, but you are being an awesome aunt to Joe, and given him more stability in these past few months than he has probably ever known.
Hugs and prayers!
Amy