Okay, I really think you are dealing with OEs and (mostly normal) jealousy and developmental asynchrony. I know you said it's "horrific" but I think I know what you really mean. smile

When they are close in age and very different temperamentally but also gifted (whew!) this is sorta inevitable. I don't think it's a LOG thing, either, but not sure (my kids are both about same ability level).

I suggest a lot of deep breathing. For all of you. The kids may very well end up being "besties" again after this period of differentiation.