Isaiah Washington Threatens to Expose Set Secrets from Greys Anatomy

Last week actor Isaiah Washington raised eyebrows after claiming some of his best teachers and neighbors were in the Ku Klux Klan [click here if you missed that]. 

Now Isaiah is threatening to reveal on set secrets from his time on Grey's Anatomy...

Back in 2007 Isaiah Washington was fired from Grey's Anatomy after calling his co-star T.R. Knight the F-word [click here if you missed that].

Now Isaiah is on Twitter threatening to tell all.