Common bathroom occurrence amongst females. When you are getting ready to urinate and there is someone that unexpectedly goes into the stall next to you. You clench up your nether regions to stop a possible loud tuft of air from escaping.
I had to pee soooooo bad earlier! Jasmine walked into the stall next to me right before the grand release and I had to do a coochie clench so I would not embarass myself.