Someone who is a big dick legend usually gets absurdly drunk and proceeds to shout out, 'big dick legend' to anyone that cares to listen.
Taxi Driver: *silence*
Mark: You certainly are one big dick legend.
Dewy: Dude, got so wasted last night, told the bouncer he was a big dick legend and he was amused.
Mark: Haha, what a big dick legend.
Mark: You big dicked legend.
Dewy: BIG DICK LEGEND!
Jero: Guys, you all know I am a big dick legend.
Everyone: *looks away*
Jero: Fine, I am going back to masturbate in my Mercedes.
Jake: You Mercedes driving cunt!
Mark: Haha Jake, you big dick legend.