Someone told me this tale:
A woman is trying to board a bus, but her skirt is too tight and she can't step up. She reaches behind her and lowers the zipper a bit and tries again. Skirt's still too tight. She reaches behind her and lowers the zipper some more. She still can't get on and lowers the zipper a third time.
Suddenly, she feels two hands on her butt, trying to push her up onto the bus. She spins around and says very indignantly, "Sir, I do not know you well enough for you to do that!"
The man responds, "Lady, I don't know you well enough for you to unzip my fly three times either!"