Why do girls and women leave panties on the floor in the bathroom?

good-looking-geek
Even when they are changing in somebody else's house because they are visiting, why do they do that? Also when people come over and the girl who lives there knows people are coming over, the girl still leaves her panties on the floor in the bathroom. Or why do girlfriends leave their panties on the floor in her boyfriend's bathroom even when the boyfriend might have a roommate?

Shouldn't that be a private thing that you don't want to advertise to anybody who happens to pass by? Shouldn't the girl care about modesty with regards to that subject?
Updates
+1 y
I had a friend who had a roommate who had a girlfriend who did that (luckily it wasn't in my apartment). And this past weekend I was on a vacation at a lake house and a lot of relatives were there and one lady did that at the vacation lake house.
Why do girls and women leave panties on the floor in the bathroom?
10 Opinion