HOLLYWOOD, CA -- The entertainment world was abuzz over the disclosure that Demi Moore was pregnant with Justin Bieber's baby.   Moore and Kutcher had recently announced their separation on what many presumed was because of Kutcher running around with other women.  But today, sources began reporting that the separation was due to an affair that Demi Moore was having with pop star Justin Bieber.  The publicists of Bieber and Moore would not comment on the story.