I am happy that this little boy has you, but my concern is that though you say he's safe, and if "something" happens, you are close enough to be right there for him, which is a Godsend to this child, but here goes the big "if", what happens if something happens? To what extent? Why wait till "something happens" to report her? Not to sound grim, if your sister is not a good mom, and your mom is in some sort of transistion with herself,is either one of them capable, other than you if there would be some emergency? Why wait till one occurs also. Being passed around,is not healthy,psychologicaly, and possibly even physically, for your nephew, he deserves a stable home, with stable parents.
Thank God, he has you, probably the only stable person in his life.
I send you many good wishes of love and luck with all of this, it is so difficult to witness this happening to a child, even a pet, too.
Take care now,
DE

(((((((((( Desirae )))))))))))))))