Rachel Weisz and Darren Aronofsky have revealed that their two-year-old son Henry is making up rude jokes.

"He's really well. He's delicious. He's just amazing," gushed The Mummy star at the Gotham Independent Film Awards in New York.

"He's got a good sense of humour. He makes up knock knock jokes that are R-rated (18-rated)."

Her fiance, who directed Mickey Rourke in the highly talked-about The Wrestler, added: "He does an R-rated (18-rated) knock knock joke in G-rated (U) language. I was talking to him about knock knock jokes, which probably won't translate in print.

"Anyway, I said to him, 'Say knock knock', so he did, and I said, 'who's there?' and he thought for a while and went, 'the doorman'. I told him that was very good, the man at the door. And I said, 'the doorman who?' and he replied, 'the doorman caca (poo)'. I thought, pretty good, he did his first poo-poo joke."