Why is your male bearded dragon shaking his head up and down to your female bearded dragon and why is your female bearded dragon waving back to your male bearded dragon?

Because their getting comfortable before they feel they can mate, they mght ater mating to kill akwardness{THEIR HORNY}

The male doing the head bobbing is showing that he is the dominant one and the female doing the arm waving is showing she is the submissive one.

Sometimes these rolls are reversed as well.