What is Gregory Ferber's identity?

"What did you say? Mr. Tu doesn't dare to drink the wine you toasted?"
"You are so arrogant, aren't you? Don't you consider the occasion? How arrogant are you to say such a thing?"
"Oh my god, Melanie, you didn't marry a fool, did you? How could there be such a stupid person!"
As Gregory Ferber said this, everyone present had extremely shocked expressions, staring at Gregory Ferber as if he was a fool.
In front of a big boss of the Imperial Capital's underground world, he said that...