I suppose it is just a sign of two people being more comfortable with each other, but as a relationship progresses you notice changes.  They aren't usually sudden; they morph from one stage to another slowly.  Maybe you don't feel so self-conscious walking out of the shower and into the bedroom with no clothes on.  Or she's not embarrassed to admit she will eat peanut butter out of the container with a spoon.

Still, on occasion you'll remember the way things used to be, and find yourself noticing the marked comparison with the current state of affairs.  Like, remember when you started dating, and she would not only close the bathroom door when she urinated but would even ask that you not be in the adjoining room?

...compared to last night, when a sudden burst of noise in bed is followed by a half-hearted "Excuse me" before she goes back to sleep.

They don't seem to cover that topic much in "Cosmopolitan" articles, do they?