It appears that Manhattan nightclub Stereo isn’t quite big enough for the likes of both John Mayer and pop star Ashlee Simpson, the little sis of John's recent ex, Jessica Simpson.Last week, Ashlee, 23, made the scene at Stereo’s celeb-filled two-year anniversary party, where her boyfriend, Fall Out Boy's Pete Wentz, was playing guest DJ for the occasion. Elsewhere in the Big Apple that evening, soft-rocker John, who had been whooping it up at Alicia Keys' record release party, was on his way to join the fun at Stereo. But sources reveal to OK! that once the songwriter, who fancies himself a comedian and who Read More >>