if you meet a stranger, he walking toward you and you noticed that he doesn't zip his pants.

what is the proper word to tell him? by not to embarrass him or lost his confident.

please reccommend coz i don't how to....

I didn't mean to stare at man's zip area pants but its just outstanding and sometime it just accidently staring without my any intention, really...

http://www.youtube.com/watch?v=yRgwEwqFyLA&feature=related