Chris Brown -- Sued Over Alleged Homophobic Beatdown

Chris Brown is being sued by the guy who claims the rapper berated him with the words, "I ain't down with that gay s***" and then beat him and broke his nose.

Parker Adams claims in his new, $3 million lawsuit .... he was outside the W Hotel in D.C. last October when Brown went nuts on him. This is the same incident for which Brown is currently being prosecuted for misdemeanor assault.

Brown has denied any misdeeds and we're told he claims Adams was the aggressor, trying to strongarm his way on his tour bus.

Adams is suing both Brown and Christopher Hollosy -- Brown's bodyguard. Adams wants $1 million from each of them for his injuries, and another $500K from each for punitive damages, to teach them a lesson.