Looks like there's one person who isn't afraid to step to Jay-Z: Robert De Niro. The Roc Nation head honcho and the award-winning actor were apparently involved in a heated exchange -- moreso due to the latter -- while attending Leonardo DiCaprio's birthday bash.

According to the NY Post, sources claim De Niro, 69, called Jay-Z, 42, "disrespectful" after failing to return a handful of phone calls made to him regarding a song he was to record for the Tribeca Film Festival -- De Niro co-founded the event in 2002. The remark was made at DiCaprio's birthday celebration earlier this week, after the actor was approached by Hov, who attempted to greet him but was met with a cold shoulder. “He told Jay that if somebody calls you six times, you call them back," a source reveals. "It doesn’t matter who you are, that is just rude.”

Reports even detail Beyonce's involvement. The R&B songstress allegedly tried to intervene, attempting to diffuse the situation. “Beyoncé came over, but that didn’t calm Bob down,” the source added. “It was the talk of the party. Everyone was saying there’s only one star in New York bigger and badder than Jay-Z, and that’s Robert De Niro. He can be quite scary when he’s angry.”

Reps for both De Niro and Jay-Z declined to comment on the verbal tiff. Do you think De Niro has a right to be annoyed or should he brush that dirt off his shoulder?

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