Oddly, this cognative dissonance didn't wake me, as the dream continued with us* going to another unfamiliar house, but this one actually did have family in it.
So, my conscious (as much as a sleeping mind is conscious) mind was expecting one thing and my sub-conscious said "not the one!". Weird.
*beats me now who was with me. I just remember he was male and not family.
** I assume we were driving. Or... something