SIN CITY star Jessica Alba is sick of playing sex kittens on screen, and would love to star in a romantic comedy. The actress says she is tired of playing the token sexy female and wants more challenging roles. She explains, "I'll leave the slutty girl to other people and I'll play the sweet, moral girlfriend who believes in love - roles that are more interesting than playing a vixen. "That's where I want to go next - a romantic comedy or something like that." The 23-year-old also has the perfect leading man in mind - George Clooney. Alba admits she may have blown her chance to co-star with the Oscar-winning actor by telling the 44-year-old heart-throb that he was old enough to be her father. She adds, "I actually told him that. That was embarrassing, but he just laughed."