BECAUSE THEY EITHER WANNA SHOW OFF THEIR UNDERWEAR OR THEY DON'T HAVE A BELT!!! Haha just kidding I have no clue. Style and reasoning behind it's originating I guess
Boys sag their pants because the think it looks cool. It originated in prison as a symbol that you would have sex with other prisoners. I'm a guy, but I think it's stupid too so I don't do it.
