According to sources close to the situation, Robert De Niro Step-too   Jay-Z at Leonardo DiCaprio's Birthday Bash.
He asked Jay why he didn't return any of his phone calls after he tried calling him six times.
Jay said to the Goodfellas Boss that he's bad with returning calls.
De Niro replied, "He thinks he's the Man but, that he was disrespectful".
Robert wanted Jay to record a Theme Song for the TriBeCa Film Festival.
www.whatshotinhiphop.com will continue to follow this Beef and keep you posted.