Chris Brown and his security crew reportedly jumped Usher at Chris Brown’s birthday party. Reportedly, the incident stemmed from Brown being upset that Teyana Taylor was at the party after she dropped out of Brown’s Michael Jackson tribute that got scrapped at this year’s AMA’s. Usher intervened and that’s when Chris directed his anger at him. When Chris and his team left, an eyewitness tells TMZ that Usher followed them behind a bunch of buses and later emerged with a bloody nose.