Rules of Etiquette

In one of those, "Is it just me; am I trippin moments?" I'd like to put in the middle of a scenario and have you tell me who should do what:

Let's say you are hanging with your significant other. Perhaps the two of you are at his parents' house in the kitchen, when his mother walks in. Now, I've been taught that you speak when you enter a room...but since it's her house (or w/e her logic may be), are you supposed to speak first?

My ppl speak when they walk in the house, regardless (cuz really, that's what you're supposed to do)...but evyrbody's parents aren't like that; so is it her job to speak or mine?