The Zipper

In a crowded city at a busy bus stop, a woman waiting for a bus was wearing a tight leather skirt. As the bus stopped, she became aware that her skirt was too tight to allow her leg to come up to the first step of the bus.  Slightly embarrassed and smiling to the bus driver, she reached behind to unzip her skirt a little, thinking that this would give her enough slack to raise the leg.  She tried to make the step only to discover she still couldn't.  

A little more embarrassed, she once again reached behind to unzip her skirt a little more. For the second time, she attempted the step, and, once again much to her chagrin, she could not raise her leg. 

With a little smile to the driver, she again reached behind to unzip a little more.  Again she was unable to make the step. 

About this time, a large Texan, who was standing behind her, picked her up easily by the waist and placed her gently on the step of the bus. She went ballistic and turned to the would-be Samaritan and screeched: 

-How dare you touch my body!  I don't even know who you are!

The Texan smiled and drawled:

-Well, ma'am, normally I would agree with you.  But after you unzipped my fly three times, I kinda figured we was friends.