Because when you think of Nigger Dick, you picture a big, black hairy Penis.
By the way, don't say it in front of a African American person...unless they know the just, they are from the Bahamas or you REALLY wanna get your ass kicked by some guy named Tyron.
Billy: Hell yeah Bra! Hook dat sit up!
lil Jay jay:*Spills wine on pants* Woops!
Billy: Nigger Dick!
Thank you....White Power!
yo man, i really wanna put my nigga dick in that white ho's ass, yo.
Suck my nigga dick you fuckin cracka-ass fooh!