Robert De Niro allegedly picked a fight with Jay-Z last weekend. The actor called the rap mogul out for being disrespectful in front of a collection of A-list guests including Martin Scorsese and Cameron Diaz at Leonardo DiCaprio's 38th birthday party, accusing Jay-Z of never returning his calls. A source told the New York Post
: "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.
Bob wasn't in any mood to make polite conversation. He 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 argument was over a song Jay-Z had agreed to record for the Tribeca Film Festival, but the superstar rapper never got back
to fellow Tribeca resident Robert with details about the track. The insider added: "When Jay-Z tried to make a joke of it, saying he is terrible on the phone, De Niro kept telling him that he thinks he's the man, but that he was disrespectful. Beyoncé came over, but that didn't calm Bob down. 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."