When you have rules they have to apply no matter what, I agree it is hard for JJ, but I think that you have to apply the rules the same no matter what.
I am divorced and my ex-wife does exactly what you are suggesting, now my son is way off the deep end because there are no consistent consequences for him and the rules at his mom's. However at my house we have consistent consequences and now he won't come over here because it is easier for him at his mom's. However at this time I am really afraid that he is going to end up in jail for some serious things he is now into.