re doing absolutely the right thing and
handling the tantrums the right way. They are just beginning to learn cause/effect, consequences, and relationship interactions, but they don't know the boundaries yet, so of course they'll get frustrated and have a meltdown--how else can they communicate their frustration or dissatisfaction?
With Greydon, I just let him carry on for a few minutes, letting him know I understand why he's angry by allowing it for a few moments, but ignoring it...