Chris Martin has turned into a "big kid" since wife Gwyneth Paltrow landed a role in 'Iron Man'.
The Coldplay frontman is a huge fan of the Marvel superhero and has splashed out on hundreds of copies of 'Iron Man' comics to help Gwyneth research her character.
A source told website Absolute Now: "Chris is like a big kid with this. He's ordered a whole stack of comics which he says are for Gwyneth to help her get into the role but in fact he's spent more time reading them than she has."
The mother-of-two is set to play Virginia 'Pepper' Potts, the executive assistant to Iron Man's regular alter ego, billionaire industrialist Tom Stark.
Gwyneth, 34, will star alongside Robert Downey Jr. - who will play the armour-clad hero - in the Jon Favreau-directed film, due to be released in May 2008.
Kevin Feige, president of production for Marvel Studios, said: "Gwyneth is the embodiment of a leading lady.
"She brings intelligence, poise and an incredible range of talent to this role."