My 8 year old niece (actually my cousin's daughter) is really quite spoiled. Her parents constantly bribe her to get her to do what they want.
We sometimes take vacations together. On these vacations, she insists on specific rewards just for going out.
My wife and I refuse to participate in this behavior, and we don't want to give her any presents. Yet if we don't, she demands a present, and then pitches a fit until her parents get her one instead.
We're not thrilled about exposing my 3 year old son to this behavior, but it seems unlikely we'll be able to avoid it forever (and we don't want to cut that part of our family our of our lives; my cousin and his wife are actually quite nice).
How can we mitigate the girl's behavior, and it's impact on my son? Is there a way to turn this into a positive lesson for him?