VENICE (REUTERS).- Up-and-coming Irish actor Michael Fassbender plays a sex addict in “Shame,” a movie by British video artist Steve McQueen that is vying for the top prize at the Venice film festival. It is the second lead role for Fassbender in a competition movie at this year’s festival after his portrayal of psychoanalyst Carl Jung in David Cronenberg’s “A Dangerous Method.” In Shame, the German-born Fassbender is Brandon, a handsome, 30-something executive living in New York whose only distraction from work is seducing women, masturbating at home or in the office and looking for sex on the Internet. The tightly controlled rhythm of his life begins to fall apart when his needy, dysfunctional sister Sissy, played by Carey Mulligan, arrives for an unannounced visit. Her presence, and her craving