We've heard rappers getting into beef. But, when rappers and Oscar-winning actors decide to square off, it's a whole different ball game. Today's (November 15) New York Post's Page Six column is reporting that a conversation between famed actor Robert De Niro and Roc Nation boss Jay-Z got pretty tense recently at Leonardo DiCaprio's birthday party. The column is reporting that the "Godfather" actor was upset at Mr. Carter all because the rapper never returned his string of phone calls. De Niro had reportedly reached out to Jay prior about a song he agreed to record for the Tribeca Film Festival. However, when those calls went unanswered the actor felt disrespected.

“Bob was sitting at a table, and when Jay-Z went over to say hello, De Niro told Jay that he never called him back,” said a source for the Post. "[He] wasn’t in any mood to make polite conversation [and] told Jay that if somebody calls you six times, you call them back. It doesn’t matter who you are, that is just rude.” The source also says that when Jay tried to make light of the situation by saying that he's 'terrible on the phone,' De Niro "kept telling him that he thinks he’s the man, but that he was disrespectful.”

Jay, who gave a shout-out to the actor in his 2009 smash "Empire State of Mind" ("Yeah I'm out that Brooklyn, now I'm down in Tribeca/Right next to De Niro but I'll be hood forever") was among other celebrities like Jamie Foxx, Chris Rock, Jonah Hill who attended the birthday bash.