I am hoping, for your sake, that your wife and her parents are Vietnamese. Vietnamese women are incredibly hard workers, tough as hell, smart, and really sexy.
If this is the case, just shut up and pay what you have to in order to keep your sweet little viet bouncing her buns on you.
Viet women also age really well, so you've got that going for you.
If she is NOT Vietnamese, and is from a war torn region such as latin america, Africa, or the middle east, then uh....damn, you done messed up, son.