Back to the Future III Weird Scene

This has been floating around the 'net for quite some time - probably since the movie came out - but all the movies are on tonight and reminded me of it.

In a scene at the end, one of Doc's kids makes a weird gesture; to be honest, I never noticed it until it was pointed out in a video much like the following.



I really think the kid was trying to tell his mother or the director off-camera that he needed to pee.