Robert Downey Jr. says 'Iron Man 2' is "horny".

The actor - who plays inventor Tony Stark and his title character Alter Ego in the comic book film franchise - revealed the sequel has been 'sexed up' but insists it is still family friendly.

He said: "We're horny. Not, like, can't-bring-your-kids horny. Just... horny."

Mickey Rourke - who has joined the cast to play Iron Man's new nemesis Ivan Vanko, a.k.a. 'Whiplash' - admits director John Favreau amended some details about his Russian ex-prisoner character, who invents his own suit while incarcerated.

He explained to Entertainment Weekly magazine: "I told Favreau I didn't want to just play him as a one-dimensional p***k. He let me have a cockatoo, who I talk to and get drunk with while I'm making my suit."

Despite the changes, Robert admits the cast are under pressure to match the success of the first movie but is confident they can succeed.

He said: "There are a lot more invisible eyes on us now. People are going to be more critical. That's their prerogative. In a way, there's no way to win, except to win. Big."