They were interviewed during the promotional trip in Brazil. Madden mentioned that Robb Stark is much younger in the book. Well then, maybe in the show they should stop making other characters call Robb Stark “a boy”, since as played by Madden, he’s obviously NOT a boy. And it’s especially weird to hear Cersei call him a boy, since Lena Headey looks like she’s only a few years older than Richard Madden.
http://videos.abril.com.br/veja/id/c94cc80ebe2d6bed519e0e089f3c7f51
http://videos.abril.com.br/veja/id/f83c3a81bcfef448a4a9c294d2789902