Penelope Cruz's young son made his stage debut in London this month (Dec13) by volunteering during a children's show.

The actress and her husband Javier Bardem, who are currently living in the British capital, took their two-year-old boy Leonardo to see The Snail and the Whale, an adaptation of the children's book of the same name, at the St James Theatre in Victoria.

During the show, Leonardo enthusiastically joined the cast onstage and had to be led back to his seat by his mother.

The production's director Toby Mitchell tells the London Evening Standard, "The actors were saying, 'Come on everybody, we've got to save the whale'. And this little boy decided he wanted to save the whale as well and ran on to the stage to help. He was very into the play. The child's mum - Penelope Cruz - came on stage and just gently led him off."

The couple is also parents to a baby daughter, Luna.